Three-dimensional nanoporous Ge/Sn dual-framework as novel anode for high-performance Lithium-ion batteries

Silicon is a promising anode material for high-performance Li-ion batteries as a result of its high theoretical specific capacity and elemental abundance. Currently, the commercial application of the Si-based anode is still restricted by its large volume changes during the lithiation cycles and low electrical conductivity. To address these issues, we demonstrate a facile plasma-assisted discharge process to anchor nano-sized Si particles into methanol with quick quenching. After the subsequent sintering process, we obtained a Si/SiC/C composite (M-Si). The unique structure not only allowed for the electrolyte infiltration to enhance lithium ion diffusion during charge and discharge process, but also buffered the volume expansion of silicon particles to enhance the rate capability and cycle stability. The M-Si cell electrochemical results exposed good Li-ion storage performance compared to that of the bare Si used cell (B-Si). The electrode cell consisting of M-Si exhibited remarkable enhanced cyclic stability and sustained the reversible specific capacity of 563 mAhg−1 after 100 cycles, with a coulombic efficiency of 99% at a current density of 0.1C, which is higher than that of the B-Si electrode cell that was used. Hence, the as-prepared Si/SiC/C composite is an efficient anode material for Li-ion battery applications. Moreover, these results indicate that the novel plasma-assisted discharge technique will bring a potential durable methodology to produce novel high-performance electrode materials for future advanced large-scale energy-storage applications.

Recent trends in the development of MXenes and MXene-based composites as anode materials for Li-ion batteries

Mesostructured niobium-doped titanium oxide-carbon (Nb-TiO2-C) composite as an anode for high-performance lithium-ion batteries

Novel design and synthesis of carbon-coated porous silicon particles as high-performance lithium-ion battery anodes

Silicon has attracted ever-increasing attention as a high-capacity anode material in Li-ion batteries owing to its extremely high theoretical capacity.1 However, practical application of silicon anodes is seriously hindered by its fast capacity fading as a result of huge volume changes during the charge/discharge process.2, 3 The situation becomes even worse when making it for practical application where high mass loading of active-materials (mg-Si/cm2) on current collectors is necessary for high energy density batteries.4, 5 Polymer binder, one of major components in electrode, is used to bind active materials and conducting particles together onto the current collector. The properties of polymer binders play an important role on the electrochemical performance of the electrodes, especially for the cycle life and irreversible capacity losses.6, 7 Poly(vinylidene fluoride) (PVDF) is a conventional binder and widely used in traditional LIBs because of its acceptable adhesion and wide electrochemical window. However, the non-functionalized linear chain structure of the PVDF binder can’t afford sufficient binding to high-capacity anode particles that exhibit huge volume changes.6 This requires improved binding characteristics of binders to enable the integrity of the electrodes for long-cycle life. Thus, novel polymer binders with the ability to accommodate this substantial volume changes during lithiation/delithiation of Si anodes are highly desirable. Here, we report an interpenetrated gel polymer binder for high performance silicon anode through in-situ crosslinking of water soluble poly(acrylic acid) (PAA) and polyvinyl alcohol (PVA) precursors. This gel polymer binder with deformable polymer network and strong adhesion on silicon particles can effectively accommodate the large volume change of silicon anodes upon lithiation/delithiation, leading to an excellent cycling stability and high Coulombic efficiency even at high current densities. Moreover, high areal capacity of ~4.3 mAh/cm2 was achieved based on the silicon anode using the gel PAA-PVA polymer binder with a high mass loading. In view of simplicity in using the water soluble gel polymer binder, it is believed that this novel binder has a great potential to be used for high capacity silicon anode in the next generation Li-ion battery, but also for other electrode materials with large volume change during cycling. Acknowledgements This work was supported by the Assistant Secretary for Energy Efficiency and Renewable Energy, Office of Vehicle Technologies of the U.S. Department of Energy under Contract No. DE-EE0006447.

Benefiting from ultra-high theoretical capacity, silicon (Si) is popular for use in energy storage fields as a Li–ion battery anode material because of its high-performance. However, a serious volume variation happens towards Si anodes in the lithiation/delithiation process, triggering the pulverization of Si and a fast decay in its capacity, which greatly limits its commercial application. In our study, a porous Si/Fe2O3 dual network anode was fabricated using the melt-spinning, ball-milling and dealloying method. The anode material shows good electrochemical performance, delivering a reversible capacity of 697.2 mAh g−1 at 200 mA g−1 after 100 cycles. The high Li storage property is ascribed to the rich mesoporous distribution of the dual network structure, which may adapt the volume variation of the material during the lithiation/delithiation process, shorten the Li–ion diffusion distance and improve the electron transport speed. This study offers a new idea for developing natural ferrosilicon ores into the porous Si-based materials and may prompt the development of natural ores in energy storage fields.

Silicon is considered as one of the most promising anodes alternative, with a low voltage and a high theoretical specific capacity of ~4200 mAh/g, for graphite in lithium-ion batteries. However, the large volume change and resulting interfacial changes of the silicon during cycling cause unsatisfactory cycle performance and hinder its commercialization. In this study, electrochemical performance and interfacial properties of silicon nanowires (SiNWs) which are prepared by the Cu-catalyzed chemical vapor deposition method, with 1 M LiPF6/EC + DMC (1:1 v/v) containing 2 wt % or no vinylene carbonate (VC) electrolyte, are investigated by using different electrochemical and spectroscopic techniques, i.e., cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS) techniques. It is shown that the addition of VC has greatly enhanced the cycling performance and rate capability of SiNWs and should have an impact on the wide utilization of silicon anode materials in Li-ion batteries.

Lithium-ion (Li-ion) batteries as an energy storage device have drawn significant attention due to increasing demand especially in transportation, mobile, and renewable energy applications. Despite their wide utilization, the improvement of Li-ion batteries’ performance, including the enhancement of energy density, stability, and safety, remains a big challenge to overcome. Carbon nanostructures (1D, 2D, 3D) show potential as the anode materials for Li-ion batteries which possess high stability and Li-ion conductivity, yet they offer low capacity. Contrarily, metalloids and transition metal oxides materials, which show high capacity, suffer low Li-ion conductivity and exhibit volume expansion during charge/discharge. Combining these materials with carbon nanostructures to create carbon-based nanocomposites as the anode materials for Li-ion batteries is considered one of the most lucrative strategies to achieve improved performance. These composites form high stability, high conductivity, and high-capacity anode materials. Furthermore, the addition of heteroatoms to carbon nanostructures also significantly increases capacity. Herein, we intensively discuss several categories of carbon-based nanocomposites and the effect on their properties as well as performance (initial charge/discharge capacity, cycling performance). In addition, several future prospects and challenges are addressed.

Porous one-dimensional Mn3O4/CNFs composites are fabricated and used as anode materials for Li-ion batteries; they exhibit excellent electrochemical performance.

“Two-dimensional materials as electrodes” is believed to be one of the key solutions for the development of future battery technologies. Based on the first-principles calculations, we predict that a metallic carbon allotrope (net W), with high electrochemical performance, can be served as an anode material for Li-ion batteries (LIBs). The net W exhibits metallic conductivity, and the conductivity is excellently maintained after Li adsorption. Specifically, upon Li intercalation, only slight lattice variations (<1.5%) occur, which ensures a good cycling stability. The low diffusion barriers of 0.4 eV and the moderate average open circuit voltage of 0.42 V are in between those of the currently used anodes, graphite, and TiO2. Most remarkably, the storage capacity can be up to 1675 mA h g−1, which is about 4.5 times larger than that of the commercial graphite anode. The present findings identify that net W could be an excellent anode material for the application in LIBs.

Nowadays, energy and environmental issues have become the top priority among a series of global issues. Fossil fuels as the dominant source are depleted fast and usually lead to some environmental problems. Heavy metal pollution has posed a severe threat to environment and public health. Metal-organic frameworks (MOFs), as a very promising category of porous materials, have attracted more and more interest in research communities due to their extremely high surface areas, diverse nanostructures and unique properties. To meet the ever-increasing energy demand and tackle the heavy metal pollution in water, MOFs can function as ideal templates to prepare various nanostructured materials for energy and environmental cleaning applications. The aim of this dissertation is to design and synthesize metal-organic frameworks (MOFs) derived nanomaterials with desirable structures, morphologies and compositions for energy applications in Li-ion batteries (LIBs), dye-sensitized solar cells (DSSCs) and electrocatalytic water splitting and environmental application in removal of heavy metal from aqueous systems. Their performances are mainly dependent on the characteristics of nanostructured materials. Briefly, the first two projects are focused on synthesis of ZIF-8 derived N-doped porous carbon and ZIF-67 derived ultrafine Co3O4 nanoparticles/carbon nanotube composites as high-performance anode materials for Li-ion batteries. The third project concentrates on synthesis of CoNi alloy embedded carbon nanocages derived from bimetallic organic frameworks for DSSCs. In addition, MOFs-derived CoNi and CoNx@Co/N-doped carbon tubes are synthesized and evaluated as low-cost electrocatalysts for efficient oxygen evolution reaction (OER). The last project is focused on study of ZIF-8 as an efficient absorbent for removal of copper ions from wastewater.

A reduced graphene oxide/SnO2/polyaniline nanocomposite for the anode material of Li-ion batteries

Structural and electrochemical properties of SnO2-carbon composite aerogels for Li-ion battery anode material

Synthesis and electrochemical properties of La-doped Li4Ti5O12 as anode material for Li-ion battery

Since high capacity small rechargeable ion storage batteries are greatly required due to the increasing development of mobile technologies, search for new types of electrode materials with superior electrochemical properties are being explored. From its synthesis, graphene and its derivatives have been hypothesised as potential candidates for the anode material for Li-ion batteries (LIB) for their excellent electronic properties. In this work, first-principles simulation has been performed to investigate structural, electronic, adsorption and electrochemical properties of LIB where three different nitrogen-doped graphene oxide nanosheets (NDGO), with one, two and three oxygen atoms, have been chosen as anode materials with density functional theory using GGA-PBE functional. Our electrode materials predict superior structural stability without significant structural deformation. We have found that the Li+ ions are adsorbed on the electrode materials with favourable adsorption energy of 2.68 eV. The theoretical specific capacity has been found to be 1150 mAh/g which is three times higher than conventional bulk graphite. Moreover, during the lithiation process, the open-circuit voltage is found to be of 2.19 V which is benign for suppressing the dendrites formation. Our investigations provide an indication to develop better anode materials with high structural stability and high-capacity Li-ion batteries.