Quantifying Aging-Induced Irreversible Volume Change of Porous Electrodes

One of the biggest obstacles to the widespread adoption of fully electrified vehicles is the limited volumetric/gravimetric energy density of lithium-ion batteries to achieve driving ranges comparable to vehicles with internal combustion engines. Electrode thicknesses are being increased to enhance the energy density of the battery cells. Furthermore, the space within the confinements of the cell housing is utilized as much as possible. Today’s state-of-the-art (SoA) electrode materials exhibit volume and Young’s modulus change during formation and cycling, e.g. a volume change up to ~10% for graphite [1] and a threefold increase of the Young’s modulus of the graphite active particles [2]. This leads to a pressure build up within the cells due to reversible and irreversible volume changes, especially of the anode materials, during cycling. The optimized packing for SoA electrodes and the volume changes of the electrodes result in increased electrochemical/mechanical interactions that leads to stress inside the cells.In this work, the interactions between mechanical bracing and aging are studied for large format prismatic 94 Ah lithium-ion battery cells [3]. The impact of external bracing is shown for lithium-ion cells cycled up to over 7000 cycles with 100% depth of discharge (Figure 1 (a)), where the braced cells show an enhanced performance in the region of 80% state of health (SOH). The braced cells reach this threshold around 900 cycles later compared to the unbraced cells. Furthermore, the unbraced cells have a thickness change of around 17.5% after more than 7000 cycles (Figure 1 (b)). After cycling, the cells are examined with post-mortem analysis, showing significantly increased aging phenomena (e.g. lithium plating) in the unbraced cell compared to the braced cell. Inductively coupled plasma optical emission spectrometry (ICP-OES) analyses confirm these assumptions (Figure 1 (c) + (d)). In contrary to the enhanced lithium plating on the anode of the unbraced cell, X-Ray diffraction (XRD) show that bracing leads to an increased structural cathode degradation compared to the unbraced cells. Those ex-situ post-mortem experiments were also confirmed by electrochemical tests in laboratory cells, showing only small capacity fading of the aged anodes of the braced cell compared to unaged reference anode cells. Nevertheless the main factor for capacity loss inside the prismatic 94 Ah cells is the loss of lithium inventory.External pressure on cells is beneficial to guarantee sufficient contact of the components within an electrode stack and hence decreased aging phenomena mainly on the anode. The downside of the increased pressure on the cells are the significantly increased morphological and structural degradation of the cathode, which, however, plays a minor role in the overall cell degradation. The external bracing results in a more ‘homogeneous’ aging over the entire cell with only little locally different degradation characteristics.

A non-linear model for elastic dielectric crystals with mobile vacancies

TATB (triaminotrinitrobenzene) crystals are graphitic in structure. In compacted form, with or without binder, TATB undergoes irreversible volume changes upon thermal cycling. This "ratchet growth" (RG) can change geometry and reduce density by several percent, however, the mechanism responsible remains unknown. We have conducted independent studies to shed light on the nature of RG characteristics. Using thermal mechanical analysis and dilatometry, strain values are measured in real time as temperature cycling protocols are varied. Initial work on PBX 9502 (95 weight% TATB) has led to new studies on dry-pressed TATB cylinders, thus eliminating binder contributions to the thermal response. Our results clearly show that the magnitude of RG over two different temperature ranges depends on the thermal history of the specimen. In addition, we have shown that for dry-pressed TATB, the RG magnitude over a given temperature range may depend on the temperature at which the specimen was compacted from molding powder. A pressing temperature of 130°C led to specimens with significantly lower RG growth magnitude than specimens pressed at 30 or 80°C. These data and their insights are being used to inform RG models. LA-UR 11-04058.

Regarding the negative electrode, the most used electrode material in commercially available lithium-ion batteries (LIBs) up to the present day is graphite.1 Upon battery operation, an irreversible volume change in the microporous structure of the graphite electrode is detected. It is associated with the formation of the solid-electrolyte interphase (SEI) within the first cycles and an irreversible thickness increase of the electrode. Consequently, one observes a change in the electrode’s porosity after the initial formation cycles.2,3 Next to irreversible microstructure changes, one observes reversible changes in the microstructure associated with the intercalation of Li-ions into the host structure of the graphite particles upon charging the battery. The electrode particles expand during this process, increasing particle volume by ~13% when fully lithiated.4 In commercial LIBs, electrode materials, separators, and current collectors are tightly packed for a high volumetric energy density. This restricts the thickness expansion of the electrodes.5 Consequently, the graphite particles must expand into the internal pores of the electrodes, resulting in a decrease in the void volume of the porous network. Since the porous electrodes and the separator are filled with the electrolyte and the particle expansion of graphite is more significant than that of the active material in the positive electrode, one observes electrolyte motion in commercial LIBs during charge and discharge. It can be tracked by techniques requiring neutron beam facilities or expensive devices such as X-ray CT instruments.2,6 Recently, Aiken et al. developed a relatively simple apparatus to track the electrolyte motion by monitoring the changing moment of inertia of cylindrical cells during operation and simplifying the approach to study the discussed effect.In this study, we developed a method to track the reversible change of the microporous structure of an artificial graphite (MAGE-5, Hitachi, Japan) with an LP572 electrolyte (1 M LiPF6 in EC:EMC 7:3 w:w with 2 wt% VC, Gotion) during a charge and discharge cycle after formation employing electrochemical impedance spectroscopy (EIS) and operando dilatometry with both cell setups having a 1.5 bar cell compression Since the electrode’s microstructure is connected to the macroscopic properties using the MacMullin number of:NM=τ/ε=RIon·A·κ/dit correlates the porosity , electrodes thickness , ionic pore resistance , area of the electrode , conductivity of the electrolyte , and the tortuosity .8 Thus, we analyzed the change of the ionic pore resistance of graphite electrodes employing EIS in a MAGE//Li half-cell setup with a micro-reference electrode and a free-standing graphite electrode.Due to the particle expansion, we monitor an increase of the ionic pore resistance of up to 40% during charging, i.e., lithiation, of the graphite electrode.Next, we determined the SOC-dependent increase in thickness of the graphite electrode revealing a reversible thickness increase of 3%. Knowing the relation of porosity and tortuosity in a generalized Bruggeman form and using Equation 1 as described above with a constant electrode area and assuming a constant electrolyte conductivity , allowed us to extract the relative SOC-dependent decrease in porosity and void volume of the electrodes. At the end of the charge, both values decreased by approx. 10% and 9%, respectively, confirming the electrolyte repression from the graphite electrode.

Widespread adoption of electric vehicles (EVs) largely depends on the development of efficient battery systems having high energy density with the capability of fast charging. In this regard, lithium (Li) metal-based batteries, such as Li-Oxygen and Li-Sulfur batteries, can provide much higher energy density compared to that of Li-ion batteries. However, low rate-capability of both Li-Oxygen and Li-Sulfur cells hinders their practical utilizations. It has been found that transport limitations in the electrolyte play a major role in affecting the rate-capability of the cells. Therefore, identifying a suitable electrolyte with high ionic conductivity is an essential requirement to improve the rate-capability of these batteries. Additionally, a desired electrolyte must also be stable toward the electrode processes in the cell. Glyme-ether based electrolytes, in these instances, are a preferred class of electrolytes for both Li-Oxygen and Li-Sulfur batteries due to their acceptable compatibility with Li metal as well as with the porous carbon electrodes. Nevertheless, the length of the glyme-ethers dramatically affects the ionic conductivities of the electrolytes and decides the rate-capability of the battery. Therefore, in this work we have investigated the viability of fast Li-plating in different glyme-ether electrolytes and critically analyzed the effects of ion-transport and also assessed the relative stabilities of the electrolytes during Li stripping/plating processes.The present study involves investigation of Li stripping/plating in six different electrolytes using three glyme-ethers, diglyme (G2), triglyme (G3) and tetraglyme (G4), as the electrolyte solvents with lithium nitrate (LiNO3) or lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) as the Li salts (1 M) and lithium bromide (LiBr) as an additive (0.05 M). It has been found that the ionic conductivity of the electrolyte increases as the glyme becomes smaller or highly associated LiNO3 is replaced with LiTFSI. As a result, both smaller glymes and LiTFSI help to achieve Li-plating at faster rates. However, unfortunately, stability of Li-plating in terms of Coulombic efficiency and overall cycle-life decreases in smaller glymes or in LiTFSI as the Li salt and detailed investigations reveal formation of unstable SEI to be responsible for lower stability of Li-plating in these electrolytes. Our results show that the consequences of increasing the ionic conductivity of the electrolyte by simply changing the glyme-ether solvent in Li-metal batteries are quite complex and warrant careful consideration of their relative stabilities with the electrode. All the results, in depth analyses and future perspectives of this work will be discussed during the presentation.

The demand for extremely fast-charging (XFC, ≤10-min) lithium-ion batteries (LIBs) is rapidly increasing to accelerate the widespread adoption of electric vehicles (EVs). However, achieving XFC remains a critical challenge, particularly in EV-relevant cell configurations that utilize thick electrodes and high energy densities. In such cells, conventional carbonate-based electrolytes suffer from sluggish Li+ transport and unstable interfaces, leading to severe Li plating and rapid capacity decay. Overcoming this XFC bottleneck requires engineering the electrolyte system to enable both fast Li+ transport and low-resistance interface formation.In this study, we report a molecularly engineered Li+ microenvironment realized through a methyl acetate (MA)-based high-concentration electrolyte (HCE) formulated with a fluoroethylene carbonate (3MF). Compared to a dimethyl carbonate (DMC)-based HCE, the smaller and more polar MA molecules form compact solvation clusters and a softer solvation sheath, which acts as molecular lubricants, promoting Li+ percolation through the electrolyte bulk phase. As a result, despite its high salt concentration, the 3MF electrolyte exhibits much higher ionic conductivity than conventional carbonate-based electrolytes. Furthermore, the high salt concentration induces an anion-rich Li+ coordination environment, which efficiently facilitates the Li+ desolvation process. Additionally, the anion/3MF co-derived SEI ensures low energy barriers for Li+ migration across the SEI.This 3MF electrolyte enables outstanding XFC cycling performance in graphite||NMC622 cells, retaining 98.4% capacity after 500 cycles at 10 C (6-min charging) with moderate electrode loading (3.0 mAh cm–2), and further demonstrates stable long-term cycling at 6 C with high loading (6.0 mAh cm–2), representing one of the few demonstrations of high-energy Li-ion cells capable of enduring over 500 XFC cycles without degradation. These findings highlight the critical role of solvation-level molecular design in overcoming the conventional trade-offs between fast charging and energy density, offering a viable path toward practical, high-performance XFC Li-ion batteries.

The electric vehicle's most crucial component is its battery, which provides the vehicle with power. A key element of electric vehicles (EVs) is the battery management system (BMS), which ensures the safe and efficient functioning of the battery pack. Previous research on electric vehicles has identified some drawbacks, such as lengthy charging times and the need for different charging methods depending on battery capacity and temperature. In the proposed work, the battery's state of charge and remaining capacity will be estimated by measuring the voltage and current with the use of a current sensor and temperature monitor. The novelty of the work lies in its ability to increase the range of electric vehicles. This is achieved through higher energy densities in high-voltage batteries, which allow for longer driving distances between charges. Additionally, faster charging systems can handle higher charging power levels, resulting in quicker charging times. These improvements in performance are made possible by the use of high-voltage batteries, which provide the necessary power for greater peak speeds and improved acceleration. As electric mobility becomes more widespread, the ability to accurately predict charging times based on layout becomes crucial in building user confidence, optimizing energy grid management, and promoting the widespread adoption of electric vehicles.

The widespread adoption of electric vehicles (EVs) demands on-board energy storage that simultaneously delivers high energy density for range, high power density for acceleration and regenerative braking, long cycle life, and competitive lifecycle cost [1]–[3], [7]. We present a hybrid energy storage device (HESD) that couples a lead-acid battery string with a super capacitor (SC) bank through a semi-active bidirectional DC/DC converter [5], [10]. Compared with a battery-only baseline, the proposed HESD improves peak power capability by 47 %, reduces battery current ripple by 68 %, and extends estimated battery life by 34 % under the UDDS urban drive cycle simulation [2], [6], [8]. A 10-year total cost of ownership (TCO) analysis shows a $975 net saving per vehicle, despite a $1 650 higher upfront investment, owing to fewer battery replacements and higher charging efficiency [6], [20]. Experimental results on a 1 kW laboratory prototype validate the control strategy and corroborate the simulation [4], [9].

All-solid-state batteries (ASSBs) are poised to meet the rising demand for high energy density electrochemical energy storage and safety in lithium-ion battery technology, a crucial aspect for the widespread adoption of electric vehicles [1]. However, the solid-electrolyte interphase (SEI) layer arising from chemical incompatibility and a narrow solid electrolyte electrochemical window poses a significant hurdle. The SEI contributes high resistance to ion transfer resulting in poor performance and cyclability of promising solid-state electrolyte materials [1]. Therefore, probing interfacial properties between the lithium and solid-state electrolyte is paramount to assess the interfacial changes that adversely impact battery performance through multiple charge–discharge cycles [2]. According to a review from Paul et al. there have been several studies characterizing the chemical composition of the SEI in ASSBs, but there is limited evidence probing the Li-SSE interphase structure [3]. Structural properties impact interfacial transport and are difficult to assess due to the limited quantity of material available for examination and for the “buried” nature of the interphase [4]. We implemented a Li/Li symmetric cell system to isolate the interactions between lithium and an argyrodite (Li6PS5Cl) solid electrolyte. To understand and quantify the structure of reaction layers that form and evolve at Li-SSE interfaces during cycling, we have performed interface-sensitive operando transmission X-ray Diffraction (XRD) experiments with high energy, high flux synchrotron radiation. Electrochemical cycling and electrochemical impedance spectroscopy paired with XRD measurements quantified SEI formation, degradation, and specific resistance contributions. Our results show evidence for crystalline reaction layers that evolve with time and potential providing insight into the formation and evolution of dominant crystalline phases throughout the interphase region.References Yu, C., Ganapathy, S., Eck, E.R.H. et al. Accessing the bottleneck in all-solid state batteries, lithium-ion transport over the solid-electrolyte-electrode interface. Nat. Commun. 8, 1086 (2017). https://doi.org/10.1038/s41467-017-01187-y Bhaway, S. M.; Qiang, Z.; Xia, Y.; Xia, X.; Lee, B.; Yager, K. G.; Zhang, L.; Kisslinger, K.; Chen, Y.-M.; Liu, K.; Zhu, Y.; Vogt, B. D. Operando Grazing Incidence Small-Angle X-ray Scattering/X-ray Diffraction of Model Ordered Mesoporous Lithium-Ion Battery Anodes. ACS Nano 2017, 11 (2), 1443– 1454, DOI: 10.1021/acsnano.6b06708 P. Paul, B.-R. Chen, S.A. Langevin, E.J. Dufek, J. Nelson Weker, J.S. Ko. Interfaces in all solid state Li-metal batteries: A review on instabilities, stabilization strategies, and scalability. Energy Stor. Mater. 45 (2022), pp. 969-1001, 10.1016/j.ensm.2021.12.021 Tan, S., Kim, JM., Corrao, A. et al. Unravelling the convoluted and dynamic interphasial mechanisms on Li metal anodes. Nat. Nanotechnol. 18, 243–249 (2023). https://doi.org/10.1038/s41565-022-01273-3

For widespread adoption of electric vehicles, lithium-ion batteries need to achieve energy densities of around 350 Wh/kg, cost less than $100/Wh, and be able to charge quickly within 15 minutes. The production of most inactive materials within modern Li-ion cells (e.g. separator, current collector, packaging) have already undergone tremendous optimization but many opportunities remain for improving the performance of the electrodes and reducing the cost and time of wetting, formation and aging processes. By increasing the thickness of electrodes clear opportunities exist for enhancing the energy densities of conventional cell materials and reducing cost. For example, doubling the thickness of electrodes in full cells from 50 μm to 100 μm can increase the energy density of the cell by about 16% and reduce the cost of the cell by 50% (from $249/kWh to $172/kWh)1. These benefits arise from increasing the ratio of electrode active material to inactive material within cells; however, increased thickness is often accompanied by reduced rate performance and increasingly difficult electrolyte wetting and formation processes due to the challenge of infiltrating the electrode pore structure with electrolyte and displacing gases during formation2. One emerging electrode processing technology involves the laser-ablation of small micro pores or channels into Li-ion battery electrodes to enhance their electrolyte wetting and rate performance. Pulsed lasers are increasingly being used in advanced manufacturing processes due to their ability to weld, sinter, or remove materials quickly and with very high precision. When applied to high energy density thick electrodes, micro-structuring by laser patterning has been shown to improve the rate capabilities of cells while maintaining high capacity retention3. These laser ablated pores or channels provide low tortuosity paths for lithium ions to reach deeper regions in the thick electrodes more quickly than before, limiting concentration gradients and thus reducing unwanted lithium plating at elevated rates. Despite these benefits, the utilization of ultrafast lasing ablation systems as an in-line technique to selectively remove patterned regions of active material from lithium-ion battery electrodes during production has not yet been widely adopted by the industry. In this work, we identify and manufacture laser-ablated 3D electrode architectures for enhanced Li+ transport and electrochemical performance with the hope of inspiring confidence in the benefits, practicality and cost effectiveness of the laser patterning technique. Preliminary modelling work at NREL has explored the limitations of planar electrodes for fast charge performance and the importance of microscale features for improving ion-transport4-8. With the correct pore/channel geometry, the energy density of ablated electrodes can be significantly improved compared to traditional architectures. We have combined simulation models and experimental data to optimize the 3-D laser patterning of our electrodes. Modelling elucidated the electrodes baseline transport limitations and quickly identified the most promising electrode architectures for favorable cost, energy- and power-density. Next, we used our benchtop ultrafast femtosecond laser ablation system to pattern our thick (ca. 100 µm) electrodes. After processing, the electrodes were inspected using cross-section scanning electron microscopy (SEM) so that ablation parameters such as laser wavelength, power and repetition rate could be optimized and distributions of feature sizes could be identified giving insight into the limitations of the laser system. We observed that the anode and cathode materials responded significantly different to the laser ablation process and that this must be considered during electrode preparation. Next, scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS) and x-ray diffraction (XRD) were used to probe for local chemical or structural changes in the electrodes’ with patterning to determine if the remaining active materials experienced permanent laser-induced damages. Once successful achievement of the target electrode architecture was confirmed, the benefits of the achieved 3-D patterning were investigated by cycling the electrodes in full cell coin cells and comparing their performance against standard cells with unmodified electrodes (benchmark). Cycling data clearly shows improved rate performance and capacity retention derived from the patterning of the thick graphite and NMC electrodes. Direct structuring of the electrodes has improved their ion transport and reduced lithium concentration gradients (cell polarization) resulting in high specific energy- and high power-density. While clear evidence of rapid lithium plating was observed in the standard benchmark cells at rates exceeding 1C, this has been largely mitigated in the laser ablated electrodes. Lastly, we probed the wetting of these electrodes with electrochemical impedance spectroscopy to map in real time the improved rate and extent of wetting achieved through the adoption of our 3-D laser patterns. Achieving shorter wetting times will correspond to reductions in cell manufacturing costs and is expected to present a significant market advantage. Figure 1

Humidity and temperature changes are considered to be two of the most important factors influencing the slaking and disintegration behaviour of mudrocks. An experiment in which these conditions were varied was carried out on mudrock prisms sawn dry from 12 sample blocks which had been stored in sealed plastic bags since excavation. The samples were obtained from various geological formations and parts of the country. The prisms measured 30 χ 30 χ 50 mm with the long axes perpendicular to bedding. The experiment was conducted in a climate test box using dial gauges to monitor the swells and shrinkages and a balance to monitor moisture changes. Small temperature changes were made at nearly constant humidity and these were followed by small humidity changes at constant temperature. Both the temperature and humidity changes were then increased. The prisms were also subjected to severe “day” and “night” cycles, i.e. high temperature and low humidity followed by low temperature and high humidity. At various stages during the experiment conditions were returned to the original (starting) conditions to determine whether irreversible changes had taken place. All the samples, except for one with a high initial moisture content, adsorbed moisture when they were subjected to a temperature of 20 °C and 88 per cent R.H. (original conditions). Temperature changes on their own did not affect the samples much. The mudrocks were very sensitive to humidity changes, with regard to both volume and moisture changes. Severe “day” and “night” cycles did not affect the samples more than severe humidity changes on their own. The state of expansion and the moisture conditions returned to relatively constant levels whenever the original conditions were applied during the experiment. It seems therefore that few irreversible changes took place during the experiment and that, for these mudrock samples, free water was needed to cause the visible slaking and disintegration which occurred in some of the samples when they were immersed in water.

The widespread adoption of electric vehicles using advanced battery technologies and the development of their manufacturing base in the United States are critically important for the US economy and therefor a major focus of research and development sponsored by DOE’s Office of Energy Efficiency and Renewable Energy. Materials development is often touted as the most important enabling activity, however in a rank of major cost items, manufacturing costs ranks just below the cathode components. In addition to the need to reduce costs, US R&D should also focus on new, yet-to-be-scaled processing technologies that, when developed and implemented in the US provide both a strong component of US energy security and US-based employment in the production of electric vehicle batteries. This presents a major economic opportunity to the USA, as the global electric vehicle market is expected to grow to over $100 billion in the next ten years. Advances in battery processing science and technology could lead directly to the displacement of the established non-US-based manufacturing base via creative destruction--new innovative technologies lead to new manufacturing facilities, facilities that could be built and run in the USA. Processing science and engineering has traditionally been underrepresented in federally funded electrochemical energy storage R&D. Over the last nine years, the Vehicle Technologies Office (VTO) has been building an advanced processing R&D portfolio. This includes competitively funded research at universities, small businesses, and large corporations as well as programs supported across the national laboratory complex. Processing science and technology projects organize into two general activities: scaling-up materials production and developing innovative electrode fabrication approaches. This presentation will provide an overview of the sub-program’s history and several example successes. Future research directions and scenarios for possible funding opportunities will also be discussed.

With the intensification of the contradiction between economic development, fossil fuel shortages, and severe environmental pollution, the development and widespread adoption of Electric Vehicles (EVs) have become an inevitable trend. The large-scale and disorderly charging of EVs connected to the grid will impose significant impacts on the power system, potentially leading to local overloads and threatening the security and economic operation of the grid. Therefore, this study investigates the coordinated optimization planning problem involving generators, EVs, and renewable energy sources (wind and solar). A spatiotemporal optimization strategy for EV charging scheduling is proposed. On the temporal scale, an optimal scheduling model based on unit commitment is established, aiming to minimize the operational costs of generators on the transmission grid side, PM2.5 emissions, total user charging costs, and the curtailment of wind and solar power. On the spatial scale, an optimal power flow-based scheduling model is developed to reduce distribution network losses, taking into account network security constraints and the spatial migration characteristics of EVs. The proposed EV charging scheduling strategy is simulated and analyzed on a power system model comprising a standard 10-machine transmission network and an IEEE 33-node distribution network. The results validate the effectiveness and superiority of the proposed spatiotemporal optimization scheduling strategy.

The effects of global warming highlight the urgent need for effective solutions to this problem. The electrification of society, which occurs through the widespread adoption of electric vehicles (EVs), is a critical strategy to combat climate change. Lithium-ion batteries (LIBs) are vital components of the global energy-storage market for EVs, and sodium-ion batteries (SIBs) have gained renewed interest owing to their potential for rapid growth. Improved safety and stability have also put solid-state batteries (SSBs) on the chart of top batteries in the world. This review examines three critical battery technologies: LIBs, SIBs, and SSBs. Although research has historically concentrated on heavier battery components, such as electrodes, to achieve high gravimetric density, binders, which comprise less than 5% of the battery weight, have demonstrated great promise for meeting the increasing need for energy storage. This review thoroughly examines various binders, focusing on their solubilities in water and organic solvents. Understanding binder mechanisms is crucial for developing binders that maintain strong adhesion to electrodes, even during volume fluctuations caused by lithiation and delithiation. Therefore, we investigated the different mechanisms associated with binders. This review also discusses failure mechanisms and innovative design strategies to improve the performance of binders, such as composite, conductive, and self-healing binders. By investigating these fields, we hope to develop energy storage technologies that are more dependable and efficient while also helping to satisfy future energy needs.

This review paper provides a comprehensive analysis of electric vehicles (EVs) and the various factors influencing fast charging technology. The surge in EV adoption has necessitated advancements in charging infrastructure, particularly in fast charging solutions. We delve into the technical aspects of fast charging, including its impact on battery life, charging station architecture, power grid integration, and charging protocols. Moreover, we discuss the influence of battery chemistry, temperature management, and charging infrastructure on the efficacy of fast charging. By synthesizing current research findings and industry trends, this paper offers insights into the challenges and opportunities for enhancing fast charging efficiency and accessibility, thereby accelerating the widespread adoption of electric vehicles.