Battery Performance Research Articles

Wet Chemistry Route to Li3InCl6: Microstructural Control Render High Ionic Conductivity and Enhanced All-Solid-State Battery Performance.

Thanks to superionic conductivity and compatibility with >4V cathodes, halide solid electrolytes (SEs) have elicited tremendous interest for application in all-solid-state lithium batteries (ASSLBs). Many compositions based on groups 3, 13, and divalent metals, and substituted stoichiometries have been explored, some displaying requisite properties, but the Li+ conductivity still falls short of theoretical predictions and appealing sulfide-type SEs. While controlling microstructural characteristics, namely grain boundary effects and microstrain, can boost ionic conductivity, they have rarely been considered. Moving away from the standard solid-state route, here a scalable and facile wet chemical approach for obtaining highly conductive (>2 mS cm-1) Li3InCl6 is presented, and it is shown that aprotic solvents can reduce grain boundaries and microstrain, leading to very high ionic conductivity of over 4 mS cm-1 (at 22°C). Minimized grain boundary area renders improved moisture stability and enhances solid-solid interfacial contact, leading to excellent LiNi0.6Mn0.2Co0.2O2-based full-cell performance, exemplified by stable room temperature (22°C) cycling at a 0.2 C rate with 155 mAh g-1 capacity and 85% retention after 1000 cycles at 60°C with a high 99.75% Coulombic efficiency. The findings showcase the viability of the aprotic solvent-mediated route for producing high-quality Li3InCl6 for all-solid-state batteries.

Enhancement of the electrochemical performance of zinc-silver batteries with a gold nano-scaffold.

Primary zinc-silver batteries are widely employed in military, aerospace, and marine applications. However, the development of secondary zinc-silver batteries is still a subject of on-going research. For example, these batteries suffer from rapid capacity loss during cycling due to instabilities of the zinc anode and the silver cathode. While there is a large body of work on the Zn anode, there is limited work toward stabilizing the Ag electrode and thereby achieving a long cycle life. In this work, we propose a gold-silver nanostructure where gold acts as a scaffolding material and improves the retention of structural integrity during cell cycling. We show that this nanostructure improves battery capacity as well as capacity retention after 35 cycles. Our work emphasizes the role of nanostructuring in enabling a newer secondary battery chemistry based on existing primary ones.

Densification of Alloying Anodes for High Energy Lithium-Ion Batteries: Critical Perspective on Inter- Versus Intra-Particle Porosity.

High Li-storage-capacity particles such as alloying-based anodes (Si, Sn, Ge, etc.) are core components for next-generation Li-ion batteries (LIBs) but are crippled by their intrinsic volume expansion issues. While pore pre-plantation represents a mainstream solution, seldom do this strategy fully satisfy the requirements in practical LIBs. One prominent issue is that porous particles reduce electrode density and negate volumetric performance (WhL-1) despite aggressive electrode densification strategies. Moreover, the additional liquid electrolyte dosage resulting from porosity increase is rarely noticed, which has a significant negative impact on cell gravimetric energy density (Whkg-1). Here, the concept of judicious porosity control is introduced to recalibrate existing particle design principles in order to concurrently boost gravimetric and volumetric performance, while also maintaining the battery's cycle life. The critical is emphasized but often neglected role that intraparticle pores play in dictating battery performance, and also highlight the superiority of closed pores over the open pores that are more commonly referred to in the literature. While the analysis and case studies focus on silicon-carbon composites, the overall conclusions apply to the broad class of alloying anode chemistries.

Origin of O2 Generation in Sulfide-Based All-Solid-State Batteries and its Impact on High Energy Density.

The cathode surface of sulfide-based all-solid-state batteries (SBs) is commonly coated with amorphous-LiNbO3 in order to stabilize charge-discharge reactions. However, high-voltage charging diminishes the advantages, which is caused by problems with the amorphous-LiNbO3 coating layer. This study has investigated the degradation of amorphous-LiNbO3 coating layer directly during the high-voltage charging of SBs. O2 generation via Li extraction from the amorphous-LiNbO3 coating layer is observed using electrochemical gas analysis and electrochemical X-ray photoelectron spectroscopy. This O2 leads to the formation of an oxidative solid electrolyte (SE) around the coating layer and degrades the battery performance. On the other hand, elemental substitution (i.e., amorphous-LiNbxP1- xO3) reduces O2 release, leading to stable high-voltage charge-discharge reactions of SBs. The results have emphasized that the suppression of O2 generation is a key factor in improving the energy density of SBs.

Perfluorinated Amines: Accelerating Lithium Electrodeposition by Tailoring Interfacial Structure and Modulated Solvation for High-Performance Batteries.

Modulating interfacial electrochemistry represents a prevalent approach for mitigating lithium dendrite growth and enhancing battery performance. Nevertheless, while most additives exhibit inhibitory characteristics, the accelerating effects on interfacial electrochemistry have garnered limited attention. In this work, perfluoromorpholine (PFM) with facilitated kinetics is utilized to preferentially adsorb on the lithium metal interface. The PFM molecules disrupt the solvation structure of Li+ and enhance the migration of Li+. Combined with the benzotrifluoride, a synergistic acceleration-inhibition system is formed. The ab initio molecular dynamics (AIMD) and density functional theory (DFT) calculation of the loose outer solvation clusters and the key adsorption-deposition step supports the fast diffusion and stable interface electrochemistry with an accelerated filling mode with C─F and C─H groups. The approach induces the uniform lithium deposition. Excellent cycling performance is achieved in Li||Li symmetric cells, and even after 200 cycles in Li||NCM811 full cells, 80% of the capacity is retained. This work elucidates the accelerated electrochemical processes at the interface and expands the design strategies of acceleration fluorinated additives for lithium metal batteries.

A Highly Reversible Sn-Air Battery Possessing the Ultra-Low Charging Potential with the Assistance of Light.

Aqueous Sn-air batteries are attracting a great deal of interest in recent years due to the ultra-high safety, low cost, dendrite-free and highly reversible Sn anode. However, the slurry oxygen reduction/evolution reaction (ORR/OER) kinetics on the air cathodes seriously affect the Sn-air battery performances. Although various advanced catalysts have been developed, the charge overpotentials (~1000 mV) of these Sn-air batteries are still not satisfactory. Herein, iron oxide (Fe2O3) modified titanium dioxide (TiO2) nanorods with heterogeneous structure are firstly synthesized on Ti mesh (Fe2O3@TiO2/Ti), and the obtained Fe2O3@TiO2/Ti films are further applied as catalytic electrodes for Sn-air batteries. The core-shell heterogeneous structure of Fe2O3@TiO2/Ti can effectively facilitate the conversion of electrochemical intermediates and separation of photo-excited electrons and holes to activate oxygen-related reaction processes. Density functional theory (DFT) and experimental results also confirm that Fe2O3@TiO2/Ti can not only act as the electrocatalysts to improve ORR/OER properties, but also exhibit the superior photo-catalytic activity to promote charging kinetics. Hence, the Fe2O3@TiO2/Ti-based Sn-air batteries show ultra-low overpotential of ~40 mV, excellent rate capability and good cycling stability under light irradiation. This work will shed light on rational photo-assisted catalytic cathode design for new-type metal-air batteries.

In Situ Polymerized Zwitterionic Copolymer Ionic Gel Electrolytes with High Performance for Lithium-Ion Batteries.

Gel electrolytes are a promising research direction due to their high safety. However, its poor room temperature conductivity along with complex preparation process hinder its practical application. In this article, a type of zwitterionic gel electrolyte is prepared by in situ polymerization. The introduction of charged but nonmigrating zwitterionic copolymer in the polymer chain is beneficial to the dissociation of the lithium salt, improving the ion transport of the electrolyte on this account. At room temperature, the conductivity of lithium ion reaches 9.1 × 10-4 S cm-1, which contributes to achieve excellent electrochemical performance at high rates. The assembled Li|LiFePO4 cell also shows a capacity retention rate of 90.5% after 150 cycles at 0.5 C at room temperature as well as remarkable cycle stability at 1 C. These offer a novel tactic for the efficient and safe commercial application of lithium-ion batteries.

State of Charge Estimation Method of Energy Storage Battery Based on Multiple Incremental Features

Abstract Accurately estimating the state of charge (SOC) is crucial for energy storage battery management systems as it ensures battery performance and extends lifespan. However, existing deep learning-based methods often overlook the dynamic process information during battery charging and discharging, which compromises the accuracy of SOC estimation. To address this limitation, this paper proposes a novel SOC estimation method. First, we employ differential processing on the collected voltage, current, and temperature data to capture dynamic feature changes. Next, all features are normalized to ensure they are on the same scale. Finally, the processed data is divided into sliding windows and input into the TCN-BiLSTM-Attention Net (TBANet) model for SOC estimation. The results show that compared with traditional deep learning based SOC estimation methods, adding incremental features to TBANet improves the estimation accuracy by 15.8%. The average absolute error and root mean square error of the experimental results are 0.72% and 0.91%, respectively. In addition, this approach adopts transfer learning methods to verify the strong adaptability of the proposed method on different datasets, which highlights the robustness of TBANet and its potential for wide applicability in real-world scenarios.

Quantification of Charge Transport and Mass Deprivation in Solid Electrolyte Interphase for Kinetically‐Stable Low‐Temperature Lithium‐Ion Batteries

Graphite (Gr)‐based lithium‐ion batteries with admirable electrochemical performance below ‐20 °C are desired but are hindered by sluggish interfacial charge transport and desolvation process. Li salt dissociation via Li+‐solvent interaction enables mobile Li+ liberation and contributes to bulk ion transport, while is contradictory to fast interfacial desolvation. Designing kinetically‐stable solid electrolyte interphase (SEI) without compromising strong Li+‐solvent interaction is expected to compatibly improve interfacial charge transport and desolvation kinetics. However, the relationship between physicochemical features and temperature‐dependent kinetics properties of SEI remains vague. Herein, we propose four key thermodynamics parameters of SEI potentially influencing low‐temperature electrochemistry, including electron work function, Li+ transfer barrier, surface energy, and desolvation energy. Based on the above parameters, we further define a novel descriptor, separation factor of SEI (SSEI), to quantitatively depict charge (Li+/e‐) transport and solvent deprivation processes at Gr/electrolyte interface. A Li3PO4‐based, inorganics‐enriched SEI derived by Li difluorophosphate (LiDFP) additive exhibits the highest SSEI (4.89×103) to enable efficient Li+ conduction, e‐ blocking and rapid desolvation, and as a result, much suppressed Li‐metal precipitation, electrolyte decomposition and Gr sheets exfoliation, thus improving low‐temperature battery performances. Overall, our work originally provides visualized guides to improve low‐temperature reaction kinetics/thermodynamics by constructing desirable SEI chemistry.

Quantification of Charge Transport and Mass Deprivation in Solid Electrolyte Interphase for Kinetically-Stable Low-Temperature Lithium-Ion Batteries.

Graphite (Gr)-based lithium-ion batteries with admirable electrochemical performance below -20 °C are desired but are hindered by sluggish interfacial charge transport and desolvation process. Li salt dissociation via Li+-solvent interaction enables mobile Li+ liberation and contributes to bulk ion transport, while is contradictory to fast interfacial desolvation. Designing kinetically-stable solid electrolyte interphase (SEI) without compromising strong Li+-solvent interaction is expected to compatibly improve interfacial charge transport and desolvation kinetics. However, the relationship between physicochemical features and temperature-dependent kinetics properties of SEI remains vague. Herein, we propose four key thermodynamics parameters of SEI potentially influencing low-temperature electrochemistry, including electron work function, Li+ transfer barrier, surface energy, and desolvation energy. Based on the above parameters, we further define a novel descriptor, separation factor of SEI (SSEI), to quantitatively depict charge (Li+/e-) transport and solvent deprivation processes at Gr/electrolyte interface. A Li3PO4-based, inorganics-enriched SEI derived by Li difluorophosphate (LiDFP) additive exhibits the highest SSEI (4.89×103) to enable efficient Li+ conduction, e- blocking and rapid desolvation, and as a result, much suppressed Li-metal precipitation, electrolyte decomposition and Gr sheets exfoliation, thus improving low-temperature battery performances. Overall, our work originally provides visualized guides to improve low-temperature reaction kinetics/thermodynamics by constructing desirable SEI chemistry.

3-Dimensional numerical study on carbon based electrodes for vanadium redox flow battery

Electrode materials are critical in determining the performance of Vanadium redox flow batteries (VRFB). This work aims at elucidating the difference between carbon-based electrodes for VRFB. The electrodes considered for the present study are Graphite felt, Carbon felt, Carbon paper, and Carbon cloth. To study the characteristic behavior of different electrode materials, a 3D unit cell numerical model was developed by coupling electrolyte flow and electrochemical reactions and mass transfer module apart from considering the electrode structural and material information such as porosity, permeability, thickness, conductivity, and specific area. The simulation results of this study suggest that the Graphite felt is the optimum choice as an electrode material for VRFB as it offers higher electrocatalytic activity, lower pressure drop, better performance, and lower cost. The study is also extended to a multilayer configuration of Carbon Paper and Carbon Cloth. The performance of multi-layered electrodes by stacking single sheets of Carbon Paper and Carbon Cloth electrodes are matched to meet the performance obtained with the Graphite felt electrode. It has been shown with the help of polarization curve and the pressure drop study that the performance of five layers of carbon cloth and nine layers of carbon paper match the performance of Graphite felt, approximately. The present study provides practical guidance for the design and optimization of VRFB electrodes.

Construct heterostructures of MoO3 nanorods modified with Fe2O3 rice grains to improve the performance of light-involved Li-O2 battery

Light-involved Li-O2 batteries have received widespread attention in recent years. However, slow reaction kinetics and high charge/discharge overpotentials at high current densities, as well as rapid recombination of photogenerated holes and electrons have hindered their further development. In this study, we propose a design strategy to grow Fe2O3 rice grains in situ on α-MoO3 nanorods to fabricate heterostructures for Li-O2 batteries at high current densities. The heterostructure α-MoO3@Fe2O3 serves as dual-function cathode catalysts for light-involved Li-O2 batteries by facilitating oxygen reduction/oxidation reactions and enhancing the separation of photogenerated charges, thereby effectively improving photoelectrocatalytic performance. Under light irradiation conditions, the heterostructure α-MoO3@Fe2O3 exhibits low charge/discharge overpotential (0.99 V) while demonstrating good cycling stability (stable cycling for 120 cycles at a high current density of 0.5 mA cm−2 with a fixed capacity of 0.5 mAh cm−2) and good rate performance, which significantly better than that was reported the currently popular light-involved Li-O2 batteries under a high current density

Dynamically reversible cross-linked polymer electrolytes with highly ionic conductivity for dendrite-free lithium metal batteries

High-safety PEO-based electrolytes have attracted widespread attention, but their inefficient conduction of Li ions and poor contact with electrode interfaces deteriorate the performances of rechargeable lithium metal batteries. Herein, we design a vitrimer polymer electrolyte (V-SPE-PEG) with abundant dynamic imine bonds via Schiff base reaction between aldehyde and ammonia, which achieves high ionic conductivity and good interfacial compatibility with lithium anode. The dynamic polymer network in V-SPE-PEG exhibits solid-state plasticity because reversible imine bonding reactions enable the integrity of the polymer network to be maintained while altering the cross-linked points under external stimuli. Therefore, this 3D dynamic cross-linked network effectively facilitates the polymer chain dynamics and meanwhile enhances ionic conductivity. Additionally, dynamic bond exchange fosters electrolyte flowability and self-healing during lithium deposition, promoting a tightly integrated electrode/electrolyte interface while inhibiting lithium dendrites growth. Consequently, lithium symmetric cells utilizing the V-SPE-PEG electrolyte demonstrate exceptional long-term cycling stability, surpassing 1100 h and exhibit outstanding ionic conductivity of 2.7 × 10−4 S cm−1 at 30 °C. The LiFePO4||Li battery maintains stable cycling performance at both 40 °C and 60 °C. This study introduces an innovative approach to designing solid-state electrolytes for lithium-metal batteries.

Morphology-controlled metal–organic frameworks as lithium-ion boosting molecular traps for practical semi-solid Li metal batteries

Controlling electrostatic interactions between charged molecules is crucial to enabling advanced batteries with reliable Li+ conductors. To address this issue, herein, we present a class of morphology-controlled metal–organic frameworks (MOFs) that serve as Li+ boosting molecular traps for fast Li+ conduction. A rod-like MOF is incorporated into semi-interpenetrating polymer networks to construct Li+ boosting fluidic nanochannels, which enable fast Li+ transport (σ = 1.5 mS cm−1, tLi+ = 0.76) through the ionic pathway. Molecular dynamics simulations further elucidate the Li+ transport mechanism in these MOF-based molecular traps. This unusual Li+ conduction behavior of MOF-based semi-solid electrolytes suppresses the anion-triggered ion concentration gradient and facilitates the electrochemical reaction kinetics at the electrodes, ultimately improving the rate performance and cycling retention of Li-metal cells (consisting of LiNi0.7Co0.2Mn0.1O2 cathodes and Li-metal anodes). Notably, a scalable pouch-type semi-solid Li-metal cell provides stable cycling performance for realistic batteries, exceeding those of previously reported Li batteries including porous crystalline frameworks.

The enhancement and impact of Se doping on the electrochemical properties of LiMn2O4 cathode material for Aqueous Li-ion Batteries

Spinel LiMn2O4 is a promising cathode material for lithium-ion batteries. However, due to the Jahn-Teller effect and Mn dissolution, its capacity decreases seriously in the cycle process, which hinders its wider application. In the course of our research, we discovered that a modest infusion of Se-doping is capable of significantly augmenting the oxygen vacancy within the material, improve the conductivity of the LiMn2O4 material and promotes superior battery performance. Moreover, due to Se-doped the average valence state of Mn is raised, which effectively mitigates the Jahn-Teller effect. The optimized sample exhibits high capacity, long cycle life, and superior rate capability, with an initial discharge specific capacity of 101.0 mAh·g-1 at 7C and capacity retention of 87.3% after 200 cycles. The maximum specific discharge capacity of the full battery during the cycle was 97.9 mAh·g-1, the capacity retention rate after 200 cycles was 78.2%, and the maximum energy density during the cycle is 145.1Wh·Kg-1, which was nearly twice that of the single lithium-ion battery in this paper. The effect of Se-doped on the properties of LiMn2O4 cathode materials provides a new idea for the development of high-performance spinel lithium manganese oxide cathode materials.

Improved electro-kinetics of new electrolyte composition for realizing high-performance zinc-bromine redox flow battery

Aqueous Redox Flow Batteries (ARFB) are the most prominent technology for large-scale energy storage applications. The energy density of the ARFBs is mainly determined by the electrolyte components, which highly influence the flow battery performance. In the present work, we acutely investigated the various electrolyte compositions and optimized the best electrolyte for realizing the high performance of Zn-Br2 ARFBs. The electrode kinetics, such as rate constant, exchange current density, conductivity, and diffusion coefficient, were analyzed using electrochemical techniques, cyclic voltammetry, and electrochemical impedance analysis. It was observed that zinc bromide (ZnBr2) + perchloric acid (HClO4) + 1-Ethyl-1-methylmorpholinium bromide (MEM) + N-ethyl-N-methylpyrrolidinium bromide (MEP) and ZnBr2 + zinc chloride (ZnCl2) + MEM + MEP electrolytes showed improved performance, where the redox kinetics of 2Br-/Br2 redox couple is greatly enhanced. The presence of perchloric acid unlocks the capacity of full electro-oxidation of bromide (Br-) to bromine (Br2) as it involves 1e- per Br-, which would be highly beneficial to attain high energy density. Further, Zn-Br2 RFB adopted with optimized electrolyte formulation ZnBr2 + HClO4 + MEM+ MEP shows a better round-trip efficiency and displays a stable long cycling performance over 200 cycles with an energy (EE) and coulombic efficiency (CE) of > 68% and > 92%, respectively.

Surface atomic bidirectional migration modulated electrocatalytic activity in Co2MnO4 nanoparticles

Polymetallic cationic spinel-type oxides are increasingly being used as catalysts for oxygen reduction/oxygen evolution reactions (ORR/OER). Here, we have modified the anti-spinel Co2MnO4 using a quenching strategy (CMO-Q) and demonstrated that the bidirectional migration of Co and Mn cations at the tetrahedral/octahedral positions is the essential reason for enhancing the ORR/OER performance. Electrochemical test results show that CMO-Q is better than Co2MnO4, OER initial potential decreased by 100 mV, and ORR current density increased from 4.2 to 7.3 mA cm−2 at 1600 rpm, with more stable CMO-Q-based zinc–air battery performance. Meanwhile, density functional theory calculations confirm that the primary factor contributing to the reduction of distance from the d-band center of Co and Mn to the Fermi level is the conductivity enhancement. This study offers insight into regulating the surface atomic migration and catalytic performance of spinel without compromising its stable structure.

Effect of Mn content in the Ti/Zr-based AB2 Laves type alloys on their electrochemical performance

In this work, we studied the impact of Manganese content on the structural and electrochemical properties of the AB2 Laves phase alloys. These multicomponent alloys were composed of 7 individual constituents with a composition Ti0.15Zr0.85La0.03V0.12Mn0.7+xFe0.12Ni1.2 and a variable Manganese content, x = 0.021, 0.035, 0.070. The alloys were prepared using arc melting and rapid solidification techniques. These alloys were characterized by X-ray diffraction and Scanning Electron Microscopy with X-ray Energy Dispersive Spectroscopy allowing to probe the phase-structural composition of the alloys, their microstructures, and elemental distribution among the phase constituents. The rapidly solidified alloys exhibited refined microstructures with a more uniform elemental distribution compared to their as-cast counterparts, the latter containing larger grain sizes and clustered La-rich phases. C15 and C14 Laves type structures contributed to the phase-structural composition of the alloys, with their proportions influenced by the Manganese content and the chosen preparation method. The study revealed a multi-feature relationship between the Manganese content, the phase abundances, and the electrochemical performances, with notable disparities between as-cast and rapidly solidified alloys. The alloy containing 3 wt% Manganese demonstrated the highest discharge capacity and superior activation performance for both preparation methods, suggesting the best choice when optimizing the composition of the anodes for achieving the best battery performance. The highest hydrogen diffusion rate was observed for the alloy containing 10 wt% Manganese which can be related to the catalytic role of Manganese in the processes of hydrogen exchange when present in these alloys.

Tri-sulfur radical trapping in lithium–sulfur batteries

Lithium-sulfur (Li–S) batteries have emerged as a next-generation battery technology owing to their prospects of high capacity and energy density. They, however, suffer from rapid capacity decay due to the shuttling of reaction intermediate species: Li polysulfides (LiPSs). One of the more important and intriguing PSs is the tri-sulfur radical (S3•−), observed mainly in high-donor number (DN) solvent-based electrolytes. Although this radical has been proposed to be crucial to full active material (AM) utilization, there is currently no direct evidence of the impact of S3•− on cycling stability. To gain more insight into the role of the S3•−, we studied the use of radical traps in low and high DN solvent-based electrolytes by operando Raman spectroscopy. The traps were based on nitrone and iminium cation, and S3•− was indeed successfully trapped in ex situ analysis. However, it was the ionic liquid-based trap, specifically pyridinium, that effectively suppressed S3•− during battery operation. Overall, the PS formation was altered in the presence of the traps and we confirmed the impact of S3•− formation on the Li–S battery redox reactions and show how the trapping correlates with Li–S battery performance. Therefore, stabilization of the S3•− might be a path to improved Li–S batteries.

Tailoring amino-functionalized cellulose separators for improved lithium-ion battery performance

This study aims to enhance cellulose separators for energy storage, focusing on achieving high security and superior electrolyte wetting properties. Bacterial cellulose (BC) separators were initially prepared via vacuum filtration. Subsequently, carboxymethyl cellulose (CMC) underwent amino-functionalization by successfully cross-linking polyethyleneimine (PEI) using glutaraldehyde. The amino-functionalized CMC was then composited onto the BC separator. This composite separator demonstrated excellent thermal stability at 200 °C and favorable electrolyte wetting. The amino groups in PEI enhanced Li+ migration by forming hydrogen bonds with PF6− in the electrolyte. Additionally, molecular-level hydrogen bonding between amino groups on PEI and carboxyl/hydroxyl groups in CMC regulated the separator's porosity. The abundant carboxyl groups in CMC facilitated Li+ transfer, notably boosting the lithium-ion battery's electrochemical performance. After 90 charge and discharge cycles, the discharge capacity of the battery assembled with BC/CMC-PEI composite separator is 132.8 mAh/g, which is 25.1 % higher than the 106.1 mAh/g of the battery assembled with traditional PP separator. At a current density of 2C, the minimum discharge capacity of the battery assembled with the composite separator is 71.1 mAh/g, while the minimum discharge capacity of the battery assembled with the PP separator is 53.6 mAh/g. This approach using functional group modification provides a promising approach to improving the performance of lithium-ion batteries.