Commercial Batteries Research Articles

Designing Tin and Hard Carbon Architecture for Stable Sodium‐Ion Battery Anode

The lack of anodes stability is one among key barriers to the widespread commercialization of sodium‐ion batteries (SIBs). This is attributed to graphite, a well‐known common anode material for a range of commercial batteries including lithium‐ion batteries (LIBs), which limits the insertion of sodium (Na) ions due to their large ionic size. Tin (Sn) has shown its potential as a suitable anode material because it exhibits high capacities in conversion and alloying reactions. However, it endures significant volumetric expansion and slower reaction rates during sodiation. To overcome these challenges, this work presents a novel anode material for SIBs where a 2D layered architecture of Sn with a hard carbon (HC) buffer layer is engineered using physical vapor deposition technique. This novel anode (SnHT/HC) exhibits a high initial capacity of 470 mAhg−1 and an exceptional retention of 438 mAhg−1 after 3000 cycles at 0.2C, with 99 % Coulombic efficiency. SnHT/HC testing at varying fast charge and discharge C‐rate of 5C, 10C, 15C, and 50C has shown promising results. Better electron transport and reduced volumetric changes are perceived to enhance the overall performance of SnHT/HC electrodes.

Sodium Vanadates for Metal-Ion Batteries: Recent Advances and Perspectives.

Rechargeable metal-ion batteries (MIBs) play a pivotal role in advancing the stable supply of renewable energy by efficiently storing and discharging electrical energy. In recent years, to propel the continuous advancement of MIB technology, numerous studies have concentrated on exploring and innovating electrode materials, aiming to engineer commercial batteries with high energy density, superior power density, and extended cycle life. Notably, sodium vanadates have garnered significant attention in the realm of MIBs owing to their distinctive crystal structures, abundant resource reservoirs, and exceptional electrochemical properties. This paper provides a prompt and comprehensive review of the research landscape for various sodium vanadates (such as NaxV2O5, Na1+ xV3O8, Na2V6O16·xH2O, etc.) in the domain of MIBs over the past five years. It delves into the structural characteristics, electrochemical performances, and energy storage mechanisms of these materials, while also proposing some effective strategies to augment their electrochemical capabilities. Building upon these insights and prevailing research outcomes, this review envisions the future developmental pathways of sodium vanadates for MIBs and aims to reveal the vast potential of sodium vanadates in the emerging energy storage field and provide researchers with clear insights and perspectives for developing optimal sodium vanadate electrodes.

Solid-State Lithium Batteries with In Situ Polymerized Acrylate-Based Electrolytes Capable of Electrochemically Stable Operation at 100 °C.

Solid polymer electrolytes (SPEs) typically consist of salts with mobile anions that could cause instabilities and parasitic side reactions in solid-state lithium (Li) batteries. To address this challenge, single-Li-ion conducting (SLIC) SPEs, where anions of Li salts are covalently attached to the polymer backbone, have been utilized to reduce the number of mobile anions. This approach improves the cationic transference number but is accompanied by a loss of ionic conductivity. In this work, we investigate a synergetic approach of using both a polymerizable SLIC salt and a conventional Li salt in a polymer matrix by in situ polymerization of the poly(propylene glycol) acrylate (PPGA) monomer. The synthesized hybrid SPEs show a high ionic conductivity of up to ∼2 × 10-4 S cm-1 and a relatively high Li-ion transference number of ∼0.4. With a significantly reduced fraction of mobile anions in the combined salt SPE, in situ polymerized SPE cells with a LiFePO4 (LFP) cathode achieve a stable performance for over 100 cycles at temperatures as high as 100 °C, which is unattainable with conventional Li salts or electrolytes. Furthermore, solid-state nuclear magnetic resonance spectra provide additional insights into differences in Li nucleus environments and emphasize a reduction in activation energy for hybrid SPEs due to their more open structure. This study opens the path for the fabrication of high-performance solid polymer Li batteries capable of operating at high temperatures using commercial battery fabrication equipment, as in situ polymerized acrylate-based polymers provide drop-in compatibility with conventional battery production, ease of acrylate polymerization, and inexpensive, facile SPE chemistry. We expect that further tuning of the acrylate-based SPE composition may allow further increases in its conductivity without sacrificing its electrochemical stability or mechanical properties.

Ethanolamine-modified gel electrolyte of zinc ion battery

The rapid growth of wearable electronic devices has spurred the development of flexible energy storage systems. However, the limitations of conventional rigid commercial batteries have hindered the advancement of wearable technology. Consequently, the development of stable, safe, highly flexible, and cost-effective flexible batteries has become a key focus in current battery research. Herein, we introduce a novel multifunctional flexible Prussian Blue–zinc battery utilizing a PVA-ZnCl₂ polymer gel electrolyte (EGPE) enhanced with ethanolamine (ETA), aimed at addressing the deficiencies of traditional electrolytes in terms of safety and mechanical performance. The Zn||Zn symmetric cell using EGPE electrolyte demonstrated an impressive long-term cycling stability of over 3000 hours at a current density of 0.15 mA cm−2. In contrast, the symmetrical cell using 0.8 M ZnCl2 aqueous electrolyte maintained its stability for only 400 hours. In addition, the prepared flexible zinc Prussian blue device maintained more than 65 % of its initial capacity of the device and its coulombic efficiency was close to 100 % after 400 cycles at an extreme current density of 10 A g−1. Furthermore, flexible device using the EGPE was able to maintain a stable power supply under various bending, torsion, folding and shearing conditions. Such innovative gel electrolyte demonstrated considerable prospects for utilisation in portably equipped devices and energy storage systems.

Formulating PEO-polycarbonate blends as solid polymer electrolytes by solvent-free extrusion

Liquid electrolytes are currently state-of-the-art for commercial Li-ion batteries. However, their use implicates inherent challenges, including safety concerns associated with flammability, limited thermal stability, and susceptibility to dendrite formation on the lithium metal anode, that can compromise the battery lifespan. Solid-state polymer electrolytes offer an alternative to conventional liquid electrolytes, aiming to mitigate safety, stability, and performance drawbacks. This study investigates the preparation and the comprehensive characterization of polyethylene oxide (PEO) and polycarbonate (PC) blends obtained through extrusion process. The process is solvent-free and easily scalable at the industrial level; it grants the efficient dispersion and mixing of PEO and PC. Blends at different ratios of PEO (Mw of 4 × 105 and 4 × 106 g mol˗1) and two types of PCs (namely, polyethylene and polypropylene carbonate) including lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) are prepared. Optimization and investigation of the relative effects between the application of different PCs and the variable ratios of PEO/PCs on the mechanical, morphologic and electrochemical properties of the final polymeric membranes is carried out for future applications of these systems, as efficient electrolytes in all-solid-state lithium batteries.

Chemo-mechanical instabilities in lithium cobalt oxide at higher state-of-charge in Li-Ion batteries

Transition metal oxide cathodes are widely used in commercial Li-ion batteries. However, their practical charge capacity is limited due to severe chemo-mechanical instabilities at higher charge voltage, and state-of-charge condition. Here, in situ stress and strain measurements were synchronized to probe mechanical deformations in the lithium cobalt oxide (LCO) cathode via a multi-beam stress sensor and digital image correlation, respectively. In situ mechanical measurements revealed how Li removal from the electrode structure induces deformations on the LCO composite cathodes during cycling. The structure and morphology of the LCO cathodes were further investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM) studies. Two distinct electrochemical and mechanical behaviors were identified when the LCO was charged up to 4.65 V. The LCO undergoes a compressive stress generation when charged up to 4.2 V and surface fractures on the LCO particles were detected by SEM. LCO cathode experienced significantly large contractions (negative strains) when charged up to 4.65 V, where intergranular crack formation and phase transformation were detected on the LCO particles via SEM and XRD, respectively. Overall, the study bridges complicated structural deformations with in situ analysis of mechanical degradations in LCO cathodes charged at higher voltages. The correlation is vital to understanding instability mechanisms in transition metal oxides at high voltages for alkali metal ion batteries.

Converting second-order saddle points to transition states: New principles for the design of 4π photoswitches.

Molecular photoswitches have demonstrated potential for storing solar energy at the molecular level, with power densities comparable to commercial batteries and hydroelectric energy storage. However, development of efficient photoswitches is hindered by limitations in cyclability and optical properties of existing materials. We here demonstrate that certain limitations in photoswitches based on electrocyclizations stem from the issue of controlling competition between Woodward-Hoffmann allowed and forbidden pathways. Our approach moves beyond the traditional view of activation barriers and reveals that second-order saddle points are crucial in dictating the competition between disrotatory and conrotatory pathways. These insights suggest new opportunities to manipulate the competition between these pathways through geometric constraints, fundamentally altering the connectivity of the potential energy surface. Our study also emphasizes the necessity of multi-reference methods and the need to conduct higher-dimensional explorations for competing pathways beyond photoswitch design.

A Universal Plug-and-Play Approach to In Situ Multinuclear Magnetic Resonance Analysis of Electrochemical Phenomena in Commercial Battery Cells.

Advancing electrochemical energy storage devices relies on versatile analytical tools capable of revealing the molecular mechanisms behind the function and degradation of battery materials in situ. The nuclear magnetic resonance phenomenon plays a pivotal role in fundamental studies of energy materials and devices because of its exceptional sensitivity to local environments and the dynamics of many electrochemically relevant elements. The jelly roll architecture is one of the most energy-dense and, therefore, most popular concepts implemented in pouch, prismatic, and cylindrical Li- and Na-ion cells. Such widely commercialized designs, however, represent a significant obstacle for a range of powerful in situ magnetic resonance-based methodologies due to negligible radio frequency electromagnetic field penetration through conductive metal casings and current collectors. In this work, we introduce an experimental setup that enables direct RF wave transmission through the cell terminals and current collectors, and provides efficient excitation and detection of NMR signals. An RF adapter designed as a plug-and-play device effectively turns the battery cell into an NMR probe that can be tuned to a broad range of Larmor frequencies. Due to its exceptional sensitivity, versatility, and multinuclear capability, the proposed methodology is suitable for fundamental research and industrial high-throughput screening applications. In situ NMR lineshapes provide a direct quantitative description of the chemical environments of electrochemically active elements and enable new metrics for the accurate assessment of state-of-charge (SoC) and state-of-health (SoH). Specifically, in commercial pouch cells based on lithium cobalt oxide, lithium nickel manganese cobalt oxide, and sodium nickel iron manganese oxide chemistries, 7Li and 23Na NMR data unambiguously show electrochemical transformations between intercalated and metallic forms of charge carrier ions, and reveal anisotropic magnetic properties of the electrode coating.

Synergistic promotion of reaction kinetics for LiPSs at high loadings by interfacial built-in electric field and sulfur vacancies of ternary heterostructure for high-performance Li-S batteries

The practical application of lithium-sulfur batteries is significantly impeded by the chaotic migration of lithium polysulfides, sluggish redox-reaction kinetics, and pronounced shuttle effect. Herein, a ternary heterostructure (MoS2-x/MoO2/CoP) is developed with a spontaneous built-in electric field (BIEF) and enriched sulfur vacancies. This heterostructure comprises MoS2-x, which has a high adsorption capability and work function; CoP, noted for its low work function and potent catalytic properties; and MoO2, which features a work function between that of MoS2-x and CoP and serves as a bridge with excellent electronic conductivity. An appropriate combination of the catalyst and adsorbent with sulfur vacancies controls the direction of the BIEF, realizing the “adsorption-directed migration-catalytic” reaction mechanism for sulfur species. Specifically, the synergetic effect of the BIEF and sulfur vacancies enhances electron migration from CoP to MoS2-x, which improves the lithium polysulfide (LiPSs) trapping and accelerates the directional migration of LiPSs to CoP, thereby enabling the efficient catalytic conversion of sulfur species. Consequently, batteries equipped with MoS2-x/MoO2/CoP interlayers that contain sulfur vacancies demonstrate an ultrahigh initial specific capacity of 1356.2 mA h g−1 at 0.2 C, maintaining a capacity of 708.3 mAh g−1 after 1000 cycles at 2 C. Even with sulfur loading increased to 7.13 mg cm−2, these batteries display an initial specific capacity of 7.2 mAh cm−2. This work provides a feasible approach for the rational design of vacancy-containing ternary heterostructure catalysts for commercial lithium-sulfur batteries.

Operando lateral state-of-charge inhomogeneity mapping via wavelength-resolved neutron imaging

The continuous advancement in battery technology requires the development of robust and more precise diagnostic tools for the characterization of commercial-scale battery cells. In this work, operando Bragg edge imaging (BEI), based on a time-of-flight approach, provides spatially resolved state-of-charge (SoC) mapping of a commercial-size pouch cell. The changes in the position and intensity of Bragg edges are used to track the Li intercalation into the graphite, thereby identifying the spatial distribution of various lithiation stages and the corresponding SoC. The operando wavelength-resolved BEI assessment revealed an inhomogeneous Li+ intercalation, dependent on the distance to the electrical tabs, effectively identifying features that contribute to the overall loss of performance and the accelerated degradation of battery materials. The presented results demonstrate the potential of advanced wavelength-resolved neutron imaging to be used as a diagnostic tool for commercial battery cells in a configuration without special casings or isotopes for enhancement of imaging contrast. It thus highlights its applicability for operando characterization of future batteries for portable and automotive applications.

Microporous Substrate Effect on SECM Steady State Current- A 3D Modeling Study Critical to Battery Electrode Performance

Abstract Scanning electrochemical microscopy (SECM) enables the study of mass transport in porous substrates with microscale spatial resolution, which is profoundly influenced by the substrate's architecture. Here, a 3D SECM modeling was used to compare the impact of substrate geometry on transport in three porous structures: a superposition (SP) and two high fidelity (HF-1 and HF-2) models. It was found that the steady-state current decreases with an increase in the geometric complexity from SP to HF-1 to HF-2, indicating the presence of more tortuous paths in HF-2. Despite having the same porosity and thickness values, the disparity between the SP and the two HF substrates shows the effect of microporous geometry. Our findings also demonstrated the deviation of all three substrates from Bruggeman's predictions, which highlights the significance of modeling to rationalize the transport properties in commercial battery electrodes.

Sustainable full-cell NCM||Graphite system with superior stability: The hybrid impact of sulfone-containing and flame-retardant additives on interface formation and cyclability

S-containing additives improve the performance, lifetime, and sustainability of lithium-ion batteries (LIBs) through the stabilization of electrode-electrolyte interfaces, modification of electrolyte properties, and facilitating the efficient resource utilization and rapid Li+ migration. Non-etheless, fire safety, extended shelf life, and capacity maintenance are critical concerns for commercial LIBs. Herein, a S-containing film-forming additive, including 4,4-diaminodiphenylsolfon (DADP) by incorporating flame retardancy of dimethyl methyl phosphonate (DMMP) was considered toward taking the barriers of above-mentioned challenges. Based on the calculation, the additives decompose sequentially to produce a distinct SEI via a narrower energy gap under both cathodic and anodic conditions. The NCM532||Graphite with DADP/DMMP showed the enhanced preservation and stability of structure, defined by XRD, Rietveld refinement pattern, SEM, and FT-IR. While the DMMP decreased the fire risk and lowered the capacity due to side reactions, the DADP improved the capacity loss, where the retention rate was 94.91%, 92.01%, 81.29%, and 76.22% within 100, 200, 300, and 400 cycles, respectively. The additive also maintained a capacity of 1123.115 mAhg−1 for 650 cycles, demonstrating excellent cyclability. Therefore, DADP/DMMP facilitate the formation of stable SEI layer, reduce fire risk, improve cycle stability, and offer an achievable path to develop the safe and long-lasting commercial batteries.

Accelerated commercial battery electrode-level degradation diagnosis via only 11-point charging segments

Accelerated and accurate degradation diagnosis is imperative for the management and reutilization of commercial lithium-ion batteries in the upcoming TWh era. This work proposes a framework combining both deep learning and physical modeling to extend traditional capacity degradation diagnosis to a rapid and accurate degradation diagnosis at the electrode level using only readily measurable charging current and voltage signals. Deep learning is used to rapidly and robustly predict polarization-free incremental capacity analysis (ICA) curves in minutes, which are traditionally obtained in a dozen hours, and the physical model is to quantitatively reveal the electrode-level degradation modes by decoupling them from the ICA curves. It is demonstrated that 11 points collected at any starting state-of-charge (SOC) in a minimum of 2.5 minutes are sufficient to predict reliable ICA curves with a mean root mean square error (RMSE) of 0.2774 Ah/V. Accordingly, batteries can be accurately elevated based on their degradation at both macro and electrode levels. Through transfer learning, such a method can also be adapted to different battery chemistries, emphasizing the enticing potential for rapid promotion of this work in battery degradation diagnosis.

Visualizing and Quantifying Electronic Accessibility in Composite Battery Electrodes using Electrochemical Fluorescent Microscopy

Electronic connections between active material particles and the conductive carbon binder domain govern high-energy commercial Li-ion batteries' rate capability and lifetime (LIB). This work develops an in situ electrochemical fluorescent microscopy (EFM) technique that maps fluorescence intensity to these local electronic connections. Specifically, rapid redox kinetics of an electrofluorophore translates to reaction distributions limited by the electronic accessibility of battery electrode regions and individual active material particles. This technique can visualize hot spots, dead zones, and isolated particles on the electrode surface. EFM characterization of a series of LiNi0.33Mn0.33Co0.33O2 electrodes across processing parameters finds a significant negative correlation between the number of disconnected active particles and the rate capability. This low-cost technique provides quantitative mesoscale characterization of commercial LIB electrodes with fast throughput (<60 s) to facilitate rapid research and development and provide manufacturing quality control.

Short-Circuit Detection in Lithium-Ion Batteries Using Machine Learning: Analysis and Comparison with Physics-Based Method

Early detection of short circuits in battery-powered systems is critical in preventing potential catastrophic failures. However, nascent short-circuit signatures are extremely weak and challenging to detect using existing algorithms without compromising on prediction accuracy. Traditional physics-based approaches rely on hand-crafted models to establish relationships between battery operating parameters and short resistance, which limits their ability to capture all relevant details, resulting in sub-optimal accuracies. In this study, we present a machine learning-based approach that leverages rest period voltage data to detect short circuits. Our method employs a 1D convolutional neural network (CNN) classifier/estimator that extracts temporal dynamic features relevant to the short circuit prediction problem from both the long and short tails of the rest period voltage profile. The approach is validated using commercial battery data, generated at different conditions including temperatures, and short circuits of varying severities; with prediction accuracies greater than 90% even for soft shorts of 500Ω. The key performance parameters of the 1D CNN model are compared against a physics-based short detection approach, demonstrating its superior performance and cost-effectiveness. Overall, our work represents a significant advancement in the field of short circuit detection in battery-powered systems, offering improved accuracy, efficiency, and cost-effectiveness.

Advanced Methods for Characterizing Battery Interfaces: Towards a Comprehensive Understanding of Interfacial Evolution in Modern Batteries

Batteries are complex systems operating far from equilibrium, relying on intricate reactions at interfaces for performance. Understanding and optimizing these interfaces is crucial, but challenges arise due to the diverse factors influencing their development, making comprehensive characterization essential despite experimental difficulties. Recent advancements in characterization tools offer new opportunities to explore interfacial evolution, particularly in the solid electrolyte interphase (SEI).In this perspective article, leading experts in physical-chemical characterization techniques for electrochemical systems discuss the current state-of-the-art and emerging approaches to study interfaces and their evolution in batteries. The focus here is on the capabilities, technical challenges, limitations, and requirements that these techniques must meet to advance our understanding of battery interfacial evolution. The emphasis is placed on techniques that enable probing interfaces under realistic conditions, close to commercial battery systems, and on the integration of multiple approaches within a single measurement (multimodal) to minimise variable effects.This article focuses on the most promising techniques for characterizing all phases relevant to interfacial processes, as well as their integration with correlative analyses and computational modelling. We discuss solid phase characterization with X-ray spectroscopies and microscopies (XPS, XAS, STXM, X-PEEM & XCT), Raman spectroscopies (SERS, TERS & SHINERS), solid-state NMR and electron microscopies and spectroscopies (STEM, EDSX, EELS & 4D-STEM). The liquid phase characterization is discussed in terms of solution NMR spectroscopy, TEM and optical spectroscopies, while the gas phase can be characterized using OEMS, Pressure monitoring and GCMS. Computational modelling and simulation (DFT, ReaxFF & MLIP) are also discussed

Ultrasound-enabled adaptive protocol for fast charging of lithium-ion batteries

Abstract This paper introduces an ultrasound-assisted multi-stage constant current (UA-MSCC) charging protocol to enhance the charging performance of lithium-ion batteries. In this approach, ultrasound is applied during the final portion of each multi-stage constant current (MSCC) charging phase. Experimental results demonstrate that ultrasound decreases the internal resistance of pouch cells by up to 7%, leading to significant increase in charging capacity during each MSCC stage. The overall charging time is reduced by 26% compared to the conventional constant current constant voltage (CCCV) protocol. The performance improvement delivered by this ultrasound-assisted charging approach is especially large when the battery is charged at low temperatures and to a partial capacity. Notably, the application of ultrasound improves the coulombic efficiency to levels comparable to that at the room temperature when charging in cold environments (0°C). This approach can be applied to commercial batteries to immediately improve their charging performance, and can be seamlessly integrated into battery management systems. Unlike approaches that necessitate electrode material modifications or electrolyte additives, which require a long development time, this UA-MSCC charging protocol offers a practical and easily applicable solution for improving the battery charging performance.

Deconstruction Engineering of Lignocellulose Toward High-Plateau-Capacity Hard Carbon Anodes for Sodium-Ion Batteries.

Biomass-derived hard carbon is a promising anode material for commercial sodium-ion batteries due to its low cost, high capacity, and stable cycling performance. However, the intrinsic tight lignocellulosic structure in biomass hinders the formation of sufficient closed pores, limiting the specific capacity of obtained hard carbons. In this contribution, a mild, industrially mature pretreatment method is utilized to selectively regulate biomass components. The hard carbon with a rich closed pore structure is prepared by optimizing the appropriate ratio of biomass composition. Optimized etching conditions enhanced the closed pore volume of hard carbon from 0.15 to 0.26 cm3 g-1. Consequently, the engineered hard carbon exhibited excellent electrochemical performance, including a high reversible capacity of 346 mAh g-1 with a high plateau capacity of 254 mAh g⁻¹ at 50 mA g⁻¹, robust rate capability, and cycling stability. The optimized hard carbon shows an 88 mAh g⁻¹ increase in plateau capacity compared to hard carbon from directly carbonizing bamboo fibers. This mature approach provides an easy-to-operate industrial pathway for designing high-capacity biomass-based hard carbons for sodium-ion batteries.

Upcycling the Spent Graphite Anode Into the Prelithiation Catalyst: A Separator Strategy Toward Anode-Free Cell Prototyping.

The substantial manufacturing of lithium-ion batteries (LIBs) requires sustainable, circular, and decarbonized recycling strategies. While efforts are concentrated on extracting valuable metals from cathodes using intricate chemical process, the direct, efficient cathode regeneration remains a technological challenge. More urgently, the battery supply chain also requires the value-added exploitation of retired anodes. Here, a "closed-loop" approach is proposed to upcycle spent graphite into the prelithiation catalyst, namely the fewer-layer graphene flakes (FGF), upon the exquisite tuning of interlayer spacing and defect concentration. Since the catalytic FGF mitigates the delithiation energy barrier from calcinated Li5FeO4 nanocrystalline, the composite layer of which cast on the polyolefin substrate thus enables a customized prelithiation capability (98% Li+ utilization) for the retired LiFePO4 recovery. Furthermore, the hydrophobic polymeric modification guarantees the moisture tolerance of Li5FeO4 agents, aligning with commercial battery manufacturing standards. The separator strategy well regulates the interfacial chemistry in the anode-free pouch cell (LiFePO4||Cu), the prototype of which balances the robust cyclability, energy density up to 386.6Wh kg-1 as well as the extreme power output of 1159.8W kg-1. This study not only fulfills the sustainable supply chain with graphite upcycling, but also establishes a generic, viable protocol for the anode-free cell prototyping.

Commercial Dry Batteries: Graphite Recycling and Its Application as Counter Electrodes in a Photovoltaic System

Commercial Dry Batteries: Graphite Recycling and Its Application as Counter Electrodes in a Photovoltaic System