Metal-Organic Frameworks as Electrode Materials for Lithium-Ion Battery

Owing to their high surface area, excellent electrolyte permeability and ample diffusion pathways for charge transport, porous and hollow-structured electrochemically active materials attract more attention as the electrodes. In general, the process of template preparation method is used to achieve hollow structured materials over the last few decades. However, the complicated preparation process including removal of template and surface modification often results in poor uniformity, low reproducibility, and high cost of porous structure. Moreover, it incorporates functional chemicals with specific homogeneity and dispersity into the hollow porous intercrystalline structure. These problems hinder the development and application in energy storage and conversion devices of the diversified porous and hollow-structured materials. The metal-organic frameworks (MOFs), consisting of organic linkers and coordinated inorganic clusters, appear as an excellent collection of porous crystal material series with high surface areas, high porosity, and tunable structures. However, their low conductivity and electrolyte instability limit the further use of MOFs in the field of LIBs. Recently, how electrode materials for Lithium–ion batteries (LIBs) are designed and prepare using MOFs has attracted more attention. The composite materials derived from MOFs including nanostructured porous carbons and metal oxide uaing self-sacrificial template synthetic route not only solves the problem of low conductivity but also maintains the high surface area and porous structure of MOFs, providing abundant active sites for insertion/deinsertion or adsorption/desorption; Furthermore, composite materials derived from MOFs increase the complexity of nanostructures in terms of structural units and chemical components. In particular, large pore volume and open pore structure are critical to loading guest species, accommodating mechanical strains and facilitating mass transport. In this paper, we briefly examined the production of MOF-derived materials for applications in LIBs. The optimization and modification of an MOFs morphology were implemented according to the electrode material requirement for LIBs. Moreover, the preparation of MOFs-derived electrode materials with porous, hollow, or complicated construction and their effects on electrochemical performance were described. Finally, the challenge and trend in production of electrode materials derived from MOFs were analyzed.

Metal-organic frameworks (MOFs) have recently attracted enormous interest over the past few years due to their potential applications in energy storage and gas separation. However, there have been few reports on MOFs for adsorption cooling applications. Adsorption cooling technology is an established alternative to mechanical vapor compression refrigeration systems. Adsorption cooling is an excellent alternative in industrial environments where waste heat is available. Applications also include hybrid systems, refrigeration, powerplant dry cooling, cryogenics, vehicular systems and building HVAC. Adsorption based cooling and refrigeration systems have several advantages including few moving parts and negligible power consumption. Key disadvantages include large thermal mass, bulkiness, complex controls, and low COP (0.2–0.5). We explored the use of metal organic frameworks that have very high mass loading and relatively low heats of adsorption, with certain combinations of refrigerants to demonstrate a new type of highly efficient adsorption chiller. An adsorption chiller based on MOFs suggests that a thermally-driven COP>1 may be possible with these materials, which would represent a fundamental breakthrough in performance of adsorption chiller technology. Computational fluid dynamics combined with a system level lumped-parameter model have been used to project size and performance for chillers with a cooling capacity ranging from a few kW to several thousand kW. In addition, a cost model has been developed to project manufactured cost of entire systems. These systems rely on stacked micro/mini-scale architectures to enhance heat and mass transfer. Presented herein are computational and experimental results for hydrophyilic MOFs, fluorophilic MOFs and also flourophilic Covalent-organic frameworks (COFs).

Metal-organic frameworks and their composites for advanced lithium-ion batteries: Synthesis, progress and prospects

Rechargeable lithium-ion battery is one of the most promising energy conversion and storage systems that offers high energy and powder densities, long service life and assuring safety. Performance of lithium-ion batteries crucially relies on electrochemical characteristics of electrode materials, i.e., anode and cathode materials. This dissertation work aims at developing novel electrode materials with high capacity, excellent cycling stability and remarkable rate capability for next-generation lithium-ion batteries. The effects of surface modifications for LiMn2O4 cathode materials are studied by depositing ultrathin conformal amphoteric oxides via atomic layer deposition (ALD). In the case of ZnO coating, the thickness of ZnO ALD layers can be finely optimized at atomic scale by varying ALD growth cycles. Six ZnO ALD layers demonstrate to have the optimal thickness (~ 1 nm) for the best electrochemical performance of LiMn2O4 cathodes either at room temperature or elevated temperature. Furthermore, the effects of crystalline ZrO2 ALD coating on improving elevated-temperature performance of either micro-sized or nano-sized LiMn2O4 particles are evaluated. Other work concentrates on boosting electrochemical performance of Li-excess layered transition metal oxides, which are emerging lithium-ion battery cathode materials with very high theoretical capacities but suffering from drastic initial capacity loss and poor rate capability. To solve these issues, one strategy involves preparing hierarchical functional surface modifications on Li[Li0.2Mn0.54Ni0.13Co0.13]O2 nanoparticles, which consist of nano-sized LiCoO2 shell and sub-nano-sized ZrO2 ALD coating. The other route is to completely convert Li-excess layered Li[Li0.2Mn0.54Ni0.13Co0.13]O2 to a Li4Mn5O12-type spinel product via ex-situ ion-exchanges and a post-annealing process. The enhanced electrochemical performance of Li-excess layered cathode materials is achieved from the synergetic effects of ALD oxide coating and core-shell structure, ex-situ layered-to-spinel phase transformation, and nanoarchitecture with high surface area. In addition to cathode materials, multi-shell spherical Mn0.54Ni0.13Co0.13(CO3)0.8 carbonate anode material is synthesized by a hydrothermal approach, which is combined with its lithiated yolk-shell-structured Li[Li0.2Mn0.54Ni0.13Co0.13]O2 cathode for a full battery cell exhibiting excellent electrochemical performance.

Hollow Fe3O4/carbon with surface mesopores derived from MOFs for enhanced lithium storage performance

Sodium-ion batteries are emerging as a promising alternative to traditional rechargeable batteries, such as lithium-ion and lead-acid batteries. One of the most significant advantages of sodium-ion technology is that it utilizes materials that are not only cost-effective but also environmentally friendly. The raw materials needed to produce sodium-ion batteries are widely available, leading to reduced supply chain risks and potential price volatility often associated with lithium resources. Furthermore, the transition in energy storage mechanisms and manufacturing techniques from lithium-ion batteries is seamless since the two technologies facilitate a relatively smooth integration into existing production methods, which can lead to substantial cost savings for manufacturers. As the demand for energy storage continues to grow, the shift towards sodium-ion technology represents not just an innovation but also a practical move in battery production. Among the various cathode materials being researched for sodium-ion batteries, sodium lithium manganese oxides (NLM) have garnered attention for their potential. They exhibit good capacity and energy density; however, one of the critical challenges in their application is the Jahn-Teller distortion. This phenomenon occurs during cycling due to the changes in the valence state of manganese within the structure. As the battery operates, this distortion can lead to irreversible phase changes, compromising the structural integrity of the material and diminishing its capacity over time. To address these challenges, we investigate the role of fluorine content in enhancing the structural stability and electrochemical characteristics of (Co, F)-co-doped NLM cathode materials. By incorporating fluorine into the material's composition, we reveal that the effect of Jahn-Teller distortion can be mitigated. This modification not only helps preserve the capacity of the battery over multiple cycles but also improves the overall electrochemical performance of the cathodes. The results underscore the effectiveness of co-doping strategies, combining both cationic (like cobalt) and anionic (like fluorine) ions, to enhance the properties of electrode materials. This approach could hold the key to unlocking better performance in sodium-ion batteries, ultimately contributing to the development of next-generation energy storage solutions that are more efficient and sustainable. In summary, the advances in sodium-ion battery technology signal a significant step forward in energy storage systems. By tackling the limitations of existing materials and optimizing their composition, researchers are paving the way for viable alternatives to lithium-ion technology, thereby promoting a more sustainable and cost-effective energy future.

Currently, there is a growing number of studies related to assessing the cost-effectiveness of renewable energy projects around the world. This topic is also very relevant for the Russian energy market that is otherwise dominated by oil and gas. The Russian Ministry of Energy forecasts that local power plants running on the renewable energy sources (RES) may not become economically efficient until 2025 or later. However, a research question arises: Is it possible to effectively implement RES projects in Russia without any state support? In order to answer this question, the authors need to assess the economic feasibility of seven scenarios for the construction of a solar power plant in the Orenburg region of Russia. The methodological basis of this work is the widely used in the energy sector classic method of investment analysis based on the calculation of discounted indicators: net present value (NPV), payback period (DPP) and internal rate of return (IRR) of the project. All our calculations are based on industry-specific initial capital investment estimates, energy storage equipment costs, and related annual operating costs. This led to the development of the scenarios on the basis of an analysis of the features of electricity and capacity generation in the Orenburg region, the existing options for joining the trading system of the energy market, energy storage applications, as well as the availability of the Russian government support and funding for the solar energy projects. Our results demonstrate that the economic feasibility of the development of renewable energy in Russia can become a reality. Out of the seven scenarios, three yielded the positive economic outcome (among them there were the two project scenarios without government support). These two projects featured the sale of electricity in retail markets and the installation of an additional energy storage system, despite an almost twofold increase in capital investments. The projects in question achieved the best economic results according to the three calculated criteria. In particular, the scenario that provided for the work on the retail market directly to the energy consumer receives an NPV of more than 1.5 times higher than other projects, an IRR of 10% and pays off at least 3 years faster. Achieving a positive economic result in the wholesale market was possible only in case of state support for the project. In addition, this scenario of the project numerically reached almost identical indicators, as in the case of selling energy on the retail market in the region where the power facility operates: NPV is almost 127 million rubles, IRR is within 13.9%, and DPP is 15 years. Other scenarios that do not provide for the use of energy storage systems or do not have state support for working in the wholesale market are not self-sustaining even during the 25-year life of energy equipment. These results might have practical significance and will be used in developing an approach to creating a profile of regions in terms of the advancements of renewable energy, as well as in developing strategies for the incentives of this sector in Russia.

Nickel phosphide (Ni2P/C) hollow microspheres were synthesized via a facile two‐step route based on metal‐organic framework (MOF) precursors. Unlike direct phosphating the MOF by calcination that would damage the MOF structure and that would form multiple phases, solvothermal method was able to convert the Ni‐based MOF to one‐pure‐phase nickel phosphide with the MOF skeleton maintained, as suggested by XRD, XPS, and SEM. When using as the battery‐supercapacitor hybrids electrode material, the optimized Ni2P/C exhibited the specific capacity 670.4 C/g (1676 F/g) at 1 A/g in a three‐electrode system, and a maximum energy density 42.74 Wh/kg at 764.23 W/kg in an asymmetric supercapacitor. It also delivered an energy density of 35.39 Wh/kg at 7000 W/kg with the rate capability retention of 92 % after 5000 cycles. The high specific surface area and the increased amount of electrochemically active sites endowed by the unique morphology, together with the low charge transfer resistance all contribute to the excellent electrochemical performance of the Ni2P/C material. These also indicate that solvothermal method is feasible in converting MOF to metal phosphide for the application in energy storage and conversion systems.

There is growing interest in the use of energy storage systems (ESS) to create combined “renewable energy plus storage” power plants. ESS based on lithium-ion batteries have drawn much attention due to their high energy density and low self-discharge. However, as lithium-ion batteries are still costly, a power producer should determine ESS capacity in a sophisticated manner to ensure profitability of the PV plus storage projects. During the project horizon, lithium-ion batteries undergo severe capacity degradation, which must be considered in ESS planning. The degradation rate depends on various stress factors which are affected by ESS sizes and operation. Therefore, this paper aims to propose an advanced framework for calculating the capacity of an ESS supplementing a photovoltaic system considering the effect of the size and operation of ESS on battery degradation while maximizing profitability. Depending on how batteries are used during the project horizon, two scenarios are discussed and an ESS sizing framework for each scenario is suggested. To deal with non-convexity and black-box parameters of the optimal ESS sizing problems, we introduce an iterative algorithm that finds a solution by accessing battery degradation and optimizing profitability repetitively. We adopted the South Korean market for analysis and simulation of the frameworks.

Commercial Li-ion batteries (LIBs) cannot meet the requirements in high performance energy storage systems because of its low specific capacity (372 mAh g-1) and limited rate capability [1]. For this reason, lithium-air batteries (LABs) have been researched due to their highest theoretical energy density (11,140 Wh kg-1) [2]. Metal oxides such as MnO2, Co3O4, RuO2 and LaFeO3 have attracted as a cathode catalyst for LABs since they have efficient ORR/OER catalytic effect in LAB batteries. Among them, Cobalt oxides (Co3O4) is considered as a promising candidate of cathode catalyst due to its excellent catalytic performance properties, including their initial capacity, capacity retention, and low charging voltages (4 V) [3]. However, low electrical conductivity and agglomeration of its particles will bring about negative effect such as electrode pulverization, capacity loss and poor cycling performance. To alleviate these problems, there are many strategies have been studied. One of the major methods is fabrication of Co3O4 with nanostuctures, such as nanoparticles, nanosheets, nanowires, nanoflowers which permitting the high surface area, small dimension of these nanostructured Co3O4 [4-7]. But, the aggregation of these nanostructured Co3O4 particles and the collapse of their structure during charge-discharge test or fabrication steps still hinder LAB performances. Another competitive strategy is to synthesis hybrid materials consist of nanostructured Co3O4and carbon-based materials, such as graphene, carbon nanotubes, carbon nanofibers [8-10]. This strategy helps to release the volumetric change and improve the electrical conductivity. Recently, metal-organic frameworks (MOFs) have been investigated as a nanoporous materials because of their diverse structural topologies and tunable functionalities [11]. They have used a wide range of application in catalyst, gas separation, and energy storage with no further process. More recently, MOFs can be employed for the synthesis of porous carbon materials as the self-sacrificial templates. Herein, we synthesize mesoporous Co3O4/carbon hybrid composites for LABs using aliphatic ligand-based MOFs as the precursor. Lower thermal stability of aliphatic ligand results in interconnected porous structures and uniform distribution of Co3O4 in carbonaceous matrix. When we apply this Co3O4/carbon hybrid composite to cathode catalyst for LABs, it exhibit high capacity, good rate capability, and improved cycle performance. Reference [1] L.Z. Bai, D.L. Zhao, T.M. Zhang, W.G. Xie, J.M. Zhang, Z.M. Shen, Electrochimica Acta 107 (2013) 555–561. [2] N. Imanishi, O. Yamamoto, Materials Today. 17 (2014) 24–30 [3] C. Sun, R. Li, C. Ma, Y. Wang, Y. Ren, W. Yang, Z. Ma, J. Li, Y. Chen, Y. Kim, L. Chen, J. Mater. Chem. A 2 (2014) 7188–7196. [4] Y.N. Huang, C.C. Chen, C.H. An, C.C. Xu, Y.N. Xu, Y.J. Wang, L.F. Jiao, H.T. Yuan, Electrochimica Acta 145 (2014) 34–39. [5] L. Tian, H.L. Zou, J.X. Fu, X.F. Yang, Y. Wang, H.L. Guo, X.H. Fu, C.L. Liang, M.M. Wu, P.K. Shen, Q.M. Gao, Advanced Functional Materials 20 (2010) 617–623. [6] K. Feng, H.W. Park, X.L. Wang, D.U. Lee, Z.W. Chen, Electrochimica Acta 139 (2014) 145–151. [7] X.X. Qing, S.Q. Liu, K.L. Huang, K.Z. Lv, Y.P. Yang, Z.G. Lu, D. Fang, X.X. Liang, Electrochimica Acta 56 (2011) 4985–4991. [8] Y.B. Lou, J. Liang, Y.L. Peng, J.X. Chen, Physical Chemistry Chemical Physics 17 (2015) 8885–8893. [9] G. Huang, F.F. Zhang, X.C. Du, Y.L. Qin, D.M. Yin, L.M. Wang, ACS Nano 9 (2015) 1592–1599. [10] B.W. Huang, L. Li, Y.J. Hea, X.Z. Liao, Y.S. H, W. Zhang, Z.F. Ma, Electrochimica Acta 137 (2014) 183–189. [11] D. Zhu, F. Zheng, S. Xu, Y. Zhang and Q. Chen, Dalton Trans 44 (2015) 16946-16952 Acknowledgements “This research was supported by the MSIP(Ministry of Science, ICT and Future Planning), Korea, under the “IT Consilience Creative Program” (IITP-2015-R0346-15-1008) supervised by the IITP(Institute for Information & Communications Technology Promotion)

Metal-organic frameworks (MOFs) have gained increased attention due to their unique features, including tunable pore sizes, controllable structures and a large specific surface area. In addition to their application in gas adsorption and separation, hydrogen storage, optics, magnetism and organic drug carriers, MOFs also can be used in batteries and supercapacitors which have attracted the researcher's attention. Based on recent studies, this review describes the latest developments about MOFs as battery electrode materials which are used in lithium–ion and lithium–sulfur batteries.

Cr-doped LiNi0.5Mn1.5O4 derived from bimetallic Ni/Mn metal-organic framework as high-performance cathode for lithium-ion batteries

The World's energy consumption has increased drastically over the past several decades, particularly driven by increasing population and economic activities as well as rising living standards with technological advancements. Since the industrial revolution, fossil fuels have been the major source of energy productions, which is today shown as the primary cause of the ongoing climate change and associated environmental challenges in threatening the existence of many living species and human life and comfort. According to the statistics provided by International Energy Agency (IEA),1 the global energy supply was 14 282 Mtoe in 2018 that is 115% higher than that of the value for 1973. Fossil fuels, such as natural gas, coal and oil are still playing a critical role and covering more than 80% of global energy demands. The concerns associated with global warming and depletion of energy sources have been directing the attention to renewable and environmentally-benign energy solutions. However, efficient, affordable, and nature-friendly energy storage systems are the key to using renewable energy sources effectively. In this study, a comprehensive literature search is conducted to study and bibliografically evalute Canada's energy storage research and development activities over the last five decades. The present study intends to present the cumulative picture on energy storage reseach and development efforts and assess how universities, research institutes and funding agencies have contributed to this particular field. The literature search compiles a total of fifty-year data on energy storage-related research and development activities conducted in Canada. The number of conducted studies associated with energy storage regarding research articles, books, research projects, dissertations, and patents is presented in the period from 1971 to 2021. Furthermore, the Canadian institutes are ranked based on their scholarly ouputs and publications to indicate the most productive ones in the field of energy storage based on the data presented in the literature sources. Energy storage is described as the capture of harvested energy for later use to maintain the balance fluctuations between energy demand and supply. As the world moves towards a low-carbon economy, energy storage systems are exepcted to even play a more critical role in extracting more energy from renewable resources.10 The intermittent characteristic of renewable resources, specifically solar and wind, is one of the major challenges ahead of a reliable and steady renewable energy supply. This can be avoided by storing excess energy to re-use when the renewable resources are not sufficient or unavailable. Energy storage systems can be categorized in different ways in regards to the form of converted and stored energy. Figure 1 presents an overview of energy storage system categories which are considered in this study. It is important to note that chemical energy storage allows to storage and transportation of large amounts of energy for long distances with minimal self-discharge rates, which is crucial for the distribution and effective use of renewable energy resources. Figure 2 presents the energy density of various chemical fuels and batteries. Despite possessing high energy density, environmental concerns associated with the production and consumption of fossil-based chemical fuels, e.g. diesel, gasoline or natural gas, should be adrressed. In regards to nature-friendly chemical energy storage, particularly power-to-gas chemical storage, hydrogen is attracting favorable attention nowadays. In this regard, hydrogen appears to be the lightest and most abundant chemical element in the universe, but is not available freely (by itself). However, it occurs naturally within a compound such as water (H2O); therefore, it is an intermediate energy form. Excess electricity from renewables can be utilized in hydrogen production processes, i.e. electrolysis of water, to store energy in chemical form. Power-to-hydrogen chemical energy storage is a unique and clean method, and it can be compatible with electrochemical storage since hydrogen possesses much greater energy content. One of the major challenges with hydrogen is the low calorific value per unit of volume (MJ/m3) due to its low density. This can be avoided by deploying alternative hydrogen carriers, such as ammonia. Liquefaction at atmospheric conditions, high hydrogen atom content and high energy density characteristics make ammonia a favorable medium for storage and transportation of energy. It is further to note that batteries and capacitors are devices allowing electrochemical storage of electricity. The potential energy is stored in chemical form in batteries, while capacitors are expected to store their potential energy in the form of an electric field.14 Batteries are thus most commonly used and matured options that propose high energy densities and voltages. Lithium-ion (Li-ion), sodium-sulphur (NaS), nickel-cadmium (NiCd), lead acid (Pb-acid), lead-carbon batteries, zebra batteries (Na-NiCl2) and flow batteries are the existing battery types used in various applications. Due to their high specific energy (per unit weight) and high specific energy (per unit volume), lithium batteries attract considerable attention in electrical energy storage. Capacitors can be classified as electrostatic capacitors, electrolytic capacitors, and electrochemical capacitors, among which electrochemical, so-called supercapacitors, promote the highest capacitance per unit of volume owing to a porous structure 15. As a mechanical energy storage method, pumped hydro accounts for more than 95% of the global installed energy storage capacity.15 The main advantage of mechanical energy storage is to readily deliver energy. The method is easy to adapt for conversion and storage of energy from various sourcessuch as water current, wave, or tidal. Pumped hydro, compressed air, and flywheel are the commonly practiced mechanical energy storage methods. Pumped hydro and compressed air are bound to specific geographical characteristics, which is the main restriction for the implementation of these energy storage methods. A flywheel stores the energy obtained from a rotor mass spinning at very high speeds as kinetic energy. The stored kinetic energy can be later used to produce electricity by altering the angular velocity of the flywheel through a decelerating torque and using an electric motor in reverse 16. Despite of being non-suitable for long-term energy storage, flywheels offer favorable advantages, that is, long-life spin, high energy densities and low maintenance costs, and fast charging.17 Thermal energy storage (TES) systems are effective systems to store heat in a reservoir for a period of time (defined or undefined) for later use, that is, space heating and cooling, electricity production, hot water. If the reservoir temperature is kept under the atmospheric temperature, the storage process is called cold thermal energy storage.18 Operating temperature range, capacity requirements, charging and discharging requirements are some of important parameters when choosing an appropriate TES system for a desired application. Since the major proportion of produced and consumed energy is heat around the world, TES systems carries a significant weight regarding the development of effective energy systems . Furthermore, energy losses from the systems commonly occur in the form of heat. Decreasing losses via further utilizing from waste energy is one of many way to mitigate environmental impacts, which can be accomplished by implementing TES systems in a cost effective manner. In the current study, an overview of Canada's energy storage related studies from 1971 to 2021 is presented. The scope of this study is to present the contributions of Canadian universities, research institutes and funders to energy storage research and development efforts over the last five decades. The keywords and methodology that are used for the literature search are depicted in Figure 3. The collected and compiled data for the corresponding fields are presented in figures, and results are discussed in the following sections. In this study, an online literature search is conducted on Canada's energy storage related studies over the last five decades. The current section presents collected and compiled data in charts. The findings of the conducted study are discussed in detail. The most productive institutes of Canada regarding conducting or sponsoring energy storage-related studies are presented. The documents associated with energy storage in all subject areas are presented in Figure 4. In this regard, the highest number of energy storage-related studies were conducted in the subject area of engineering in Canada from 1971 to 2021. The fields of energy and chemistry appear as the other two major subject areas in which high number of energy storage research was conducted. While compiling data, attention has been paid to any potential field conflicts concerning the multi attribution of interdisciplinary publications. Therefore, it should be noticed that chemistry may have an impact on the subject areas of biochemistry, genetics, and molecular biology. The same impact of engineering could be seen on the subject area of energy. The data collected and analysed for comparative evaluation reveals that the Canadian institutes have produced 37 386 energy storage-related academic research publications over the last 50-year period. In this regard, Figure 5A presents the breakdown of energy storage-related publications affiliated to Canada in the corresponding material types in accordance with the publication years. Figure 5A shows that studies in this field consistently increases every year. Consequently, the year 2020 appears as the most productive one in this regard as of April 2021. In the light of this trendline, predicting that the year 2021 will be more productive than 2020 would not be wrong. Figure 5B has been prepared as a heat map to show Canada's provinces where energy storage-related studies were conducted over the last 50 years. In this regard, Ontario appears as the most productive province of Canada in terms of scholarly publications. However, one has to keep in mind that Ontario has the highest number of contributing institutes/universities compared to the rest of the provinces in Canada. Figure 6 presents the breakdown of the number of energy storage-related books, book chapters, and editorials in accordance with publication years in Canada. The year 2018 was the most productive year of Canada by producing 200 documents in the corresponding classification. The other important point that should be pinned in the figure is the year 2005. Compared to the previous year, almost five times more energy storage-related books were published in 2005. Compared to 2019, the number of published books decreased almost by half in 2020. The impact of COVID-19 is recognized as one of numerous reasons behind this result. The number of energy storage-related dissertations completed in Canada over the last five decades is primarily searched through and collected from Library and Archives Canada. The search results are, in this regard, presented in Figure 7. It can be noted that the data presented in Figure 7 is based on the number of energy storage-related theses available in the library; and thus, the results are subject to change in accordance with instantaneous new data entry to the library. As of April 2021, there are 626 energy storage-related MSc and PhD theses/dissertations entered in the online system of Library and Archives Canada. The highest number of theses/dissertations was recorded in the year of 2013 with a value of 62. Based on data collected from the website of Canadian Intellectual Property Office, the number of energy storage-related patents of Canada is 11 719 for the last 50 years. The corresponding results are presented Figure 8. According to this, the year of 2018 appeared to be the Canada's most productive year in terms of patents registered under the title of energy storage. Canada is blessed with institutions that have been supporting energy storage-related research and developments by providing funds. Over the evaluated period of 50 years, the Natural Sciences and Engineering Research Council of Canada (NSERC) appears as the major funding agency for Canada's energy storage related research, development, partnership, strategic innovation and commercialization efforts and has supported more than 8500 projects in the field of energy storage. A total number of projects that have been funded by Canadian institutes have become 18021 from 1971 to 2021. It is most likely to observe a major increase in the number of projects by the impact of the recent hydrogen strategic plan of Canada. Being an excellent energy storage medium is one of many advantages of hydrogen. Therefore, there is a significant correlation in between hydrogen and energy storage research efforts. The subject matter report is already named as call-to-action for green hydrogen transition for the energy sector. In the report, the importance of dedicating more domestic resources to green hydrogen efforts to achieve the targets by 2050 is emphasized clearly (Figure 9). The development and implementation efforts of effective, affordable, and nature-friendly energy storage systems are recognized as a key requirement in achieving a green energy transition. In this regard, Canada intends to be the country leading and inspiring many others. Figure 10 shows the a number of Canadian institutes/universities that have produced more than 100 scholarly publications on energy storage under the subject area of energy. According to this, the total number of such scholarly publications has been 9125 over the past five decades. The results clearly show that there are two universities, such as University of Waterloo with 809 publications and Ontario Tech. University (formerly University of Ontario Institute of Technology) with 697 publications, leading in this particular area. University of Waterloo appears as the most productive Canadian university with a total number of 809 publications while Ontario Tech. University, which is one of the Canada's youngest universities, follows with a total number of 697 publications. The specific affiliations in the publications show that the researchers working in the productive environment of Clean Energy Research Laboratory (CERL) at Ontario Tech. have played a major role in this achievement. The data that support the findings of this study are available in Scopus, Library and Archives Canada and Canadian Intellectual Property Office with the reference number of [17], [18], and [19], respectively. These data were derived from the following resources available in the public domain: https://www.scopus.com/search/form.uri?display=basic&zone=header&origin, https://www.bac-lac.gc.ca/eng/services/theses/Pages/search.aspx, https://www.ic.gc.ca/opic-cipo/cpd/eng/search/basic.html?wt_src=cipo-patent-main.

<p indent="0mm">The pursuit of next-generation energy storage systems has intensified research on lithium-sulfur (Li-S) batteries, which offer high energy density and low cost. However, the practical application of Li-S batteries is hindered by issues such as the shuttle effect, low electrical conductivity of sulfur, and large volume changes during cycling. Organic electrode materials possess advantages such as safety, environmental friendliness, sustainability, design flexibility, and low cost, making them promising cathode materials for high-capacity lithium batteries. Among them, organosulfur has received increasing attention with the development of lithium-sulfur batteries. Similar to sulfur cathodes, organosulfur electrodes can provide a relatively high theoretical capacity based on the reversible breaking and formation of S–S bonds. However, inherent problems such as poor conductivity, sluggish redox kinetics, unsatisfactory cycling stability, and the solubility of cycling products seriously hinder the development of organosulfur cathode materials. Doping heteroatoms into organosulfur molecules to design and synthesize new organosulfur molecules is an effective strategy to improve the performance of organic sulfur cathodes. Heteroatom doping offers a versatile method to modify the electronic structure and chemical reactivity of organosulfur cathodes. By introducing elements such as oxygen (O), nitrogen (N), selenium (Se), tellurium (Te) and phosphorus (P), researchers aim to tailor the material’s properties to improve conductivity, accelerate redox reactions, stabilize electrode interfaces, and mitigate dissolution issues of reaction intermediates. Hybridized organosulfur cathode materials have received more and more attention due to their unique design strategy and flexible electrochemical modulation. Therefore, the research progress in heteroatom-containing organosulfur cathode materials is reviewed comprehensively in this paper, summarizing their applications in lithium battery systems. It primarily discusses heteroatom-containing small molecule organic sulfur and polymer organic sulfur materials, and concludes with the challenges and prospects for organic sulfur cathode materials. It covers synthetic strategies to incorporate heteroatoms, characterization techniques to elucidate their structural and electrochemical properties, and their performance as cathode materials in various battery configurations. The discussion encompasses mechanistic insights into how heteroatoms influence charge storage mechanisms, ion diffusion kinetics, and overall battery performance metrics. Despite the promising advances, challenges remain, including the precise control of heteroatom doping levels, maintaining structural integrity during cycling, and optimizing synthesis methods for scalability and cost-effectiveness. Furthermore, the environmental impact and recyclability of these materials are critical considerations for their sustainable application in energy storage technologies. Looking forward, the development of heteroatom-containing organic sulfur cathode materials holds significant potential to address current limitations and unlock new opportunities for next-generation rechargeable batteries. Future research directions focus on refining synthetic techniques, enhancing material stability and cycling performance, exploring novel heteroatom combinations, and integrating these materials into practical battery systems that meet the increasing demands for high-energy-density and sustainable energy storage solutions. In conclusion, heteroatom-doped organic sulfur cathode materials represent a significant advancement in the field of Li-S batteries. The synergistic effect of organic-inorganic hybridization, combined with the tunability of heteroatom doping, offers a promising avenue for the development of high-performance energy storage systems. Further research is needed to fully exploit the potential of these materials and to address the remaining challenges for their practical application.

Due to the high capacity and the high discharge potential, Ni-rich layered cathode materials are considered as a class of promising cathode material and attracting considerable attention. Because of the Li+/Ni2+ cation mixing, Li residues, overcharging, crystal orientation of the secondary particles, poor cycling stability and rate capability are usually received in lithium ion batteries. In this presentation, we introduce a layered NMC811 with Ni-gradients by using metal-organic framework (MOF) as precursor ( Cell Reports Physical Science , 3 (2022), 100767). The self-healing phase by forming a cation mixing layer on the surface of particles effectively improved the structural stability by suppressing the phase transition and internal cracks upon cycling. In the half-cell battery, an initial capacity of 203.5 mAh/g at 0.1 C and a capacity retention of 88.5% after 300 cycles at 1/3 C were obtained. The battery still showed a CE of 99.47% at 1/3 C after 300 cycles at 55 ℃. In addition, the full-cell battery showed a capacity retention of >86.7% with a CE of >99.86% at 1/3 C after 300 cycles. Moreover, a pouch cell delivered an initial capacity of 297.62 mAh and a CE of 99.48%, which contributed to an energy density of 216.41 Wh/kg. The capacity retention was still as high as 84.1% after 500 cycles at 1.0 C. Keywords: Li-ion batteries; Ni-rich cathode materials; MOF; Concentration gradient