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At least 379 records · Page 21

Deconvoluting the benefits of porosity distribution in layered electrodes on the electrochemical performance of Li-ion batteries

Thick Lithium Ion Battery (LIB) electrodes suffer from poor rate capability and high ionic impedance due to their thickness and mesostructure. Therefore, optimizing thick electrode architectures becomes crucial. In this work, we report a systematic assessment of the ionic resistance in heterogeneous porous electrodes through the combination of computational simulations using a 4D-resolved model and experimental measurements. The first part of the study is devoted to a general assessment of Electrochemical Impedance Spectroscopy (EIS) spectra, mapping the impact of ionic and electronic resistances on the overall impedances of uncalendered and calendered LiNi 1/3 Mn 1/3 Co 1/3 O 2 , LiFePO 4 and graphite electrodes. In the second part, in silico-generated electrodes with different porosities are used in computational EIS simulations to analyze the impact of the electrode porosity on the ionic impedance. As expected, the results show that a lower porosity leads to a higher ionic impedance because of a higher electrode tortuosity factor. Furthermore, in silico-generated electrodes with different porosities were stacked and assembled to create heterogeneities of porosity along the thickness, and used in computational EIS and galvanostatic discharge simulations. The computational results show that the porosity heterogeneity along the electrode thickness has a significant effect on the ionic impedance and capacity of the electrode. The electrode architecture with progressively decreasing porosity from separator to current collector shows the highest performance, a trend validated by our in house experimental EIS and galvanostatic discharge also reported in this manuscript. Overall, we conclude that the ionic resistance in a thick electrode can be effectively reduced through proper tuning of the porosity heterogeneity. The proposed heterogeneous electrode architectures presented here could enormously help building efficient thick electrodes for LIBs.

25 ENERGY STORAGE↗

Constructing O2/O3 homogeneous hybrid stabilizes Li-rich layered cathodes

With the advantages of high energy density and low manufacture cost, lithium-rich layered oxides (LLOs), typically with a layered O3-type structure, are regarded as promising cathodes for lithium-ion batteries (LIBs), but their broad usages are hindered by severe voltage decay over cycling. Although recent progress in O2-type LLOs has aroused interest for their less voltage decay, the critical barrier of unsatisfactory capacity retention has not been overcome yet. In this work, to tackle these handicaps, we design a new type of LLO (O2/O3-type LLO) with a homogeneous hybrid structure, where the O2 and O3 lattice stacking sequences are arranged alternatively. Benefitting from this novel O2/O3 hybrid structure, the designed material shows greatly improved voltage and capacity stability than that of pure O2- and O3-type LLOs. Revealed by in-situ synchrotron X-ray diffraction and operando differential electrochemical mass spectra, the O2/O3-hybrid LLO cathode shows a more reversible structural evolution, smaller volume change and suppressed oxygen loss during the electrochemical processes. Our approach has initiated a new way to reduce the capacity and voltage decay of LLOs, which endows great promise to the development of high-energy-density LIBs.

25 ENERGY STORAGE↗

Cross-scale modeling and experimental integration for advancing cathode electrolyte interphase studies in high energy density lithium-ion batteries

Electrochemical interfaces are critical to the performance and durability of lithium-ion batteries (LIBs). The solid electrode-electrolyte interphase (SEI and CEI) structures that form during cycling can passivate reactive surfaces, ensuring safe operation, but also may contribute to performance degradation. Understanding the microscopic factors influencing interphase formation, growth, and evolution is essential for balanced battery design. While significant research has focused on the anode-electrolyte interphase (SEI), the cathode-electrolyte interphase (CEI) remains less explored, despite its importance in high-voltage and advanced battery technologies. Challenges in conducting in-situ or operando experiments arise from the occluded nature of these interfaces and the long timescales involved, often leading to biased interpretations. A validated multi-scale, multi-physics modeling approach, integrated with advanced characterization techniques, can effectively elucidate the intrinsic stability of electrolyte and cathode surfaces, the impact of chemical heterogeneity, and the role of microstructural features on CEI performance. In conclusion, this article reviews current modeling and simulation strategies for studying CEI in advanced LIBs and highlights opportunities for future methodological advancements and experimental integration.

Cathode-electrolyte interphase↗

Lithium plating induced degradation during fast charging of batteries subjected to compressive loading

Here we report the lithium plating associated capacity loss during fast charging of compressively loaded lithium-ion batteries (LIBs). The charging and discharging of LIB under compressive loading during service may affect the cell performance or initiate localized defects in the electrodes. Pouch cells of capacity 20 mAh were compressively loaded to nominal pressures of 0–440 kPa and subjected to 10 cycles of fast charging at 1 C and 4 C. Experimental results show that cells charged at 4 C-rate experienced significant capacity fade, and applying compressive loads exacerbated the capacity loss. The coulombic efficiency study shows that active lithium loss was higher for the initial cycles before gradually reducing to a minimal capacity loss for the tenth charging cycle. The cell voltage relaxation immediately after charging was monitored to identify the stripping of plated lithium after fast charging cycles and showed that the duration of lithium stripping was higher for cells under mechanical compressive loading. Scanning electron microscopy (SEM) and electron paramagnetic resonance spectroscopy (EPR) characterization of the anode showed significantly higher lithium deposits on the anodes charged at a 4 C rate under compressive loads. These results indicate that applied mechanical compression causes increased lithium plating during fast charging of batteries.

25 ENERGY STORAGE↗

Comprehensive evaluation of commercially scalable atomic-layer-deposited alumina coating impact on full cell battery performance across varied test conditions

Atomic Layer Deposition (ALD) has emerged as a strategic enhancement method for lithium-ion battery (LIB) materials offering potential benefits and durability benefits for industrial battery production. However, the translation from laboratory achievements to commercial-scale applications has been limited. Here, this study aims to bridge this gap by comprehensively evaluating the effects of commercially scalable Al 2 O 3 ALD coatings using full pouch cell performance as a means to assess the ALD impact. We utilized large-scale slot-die coating techniques to ensure consistent electrode quality and tested four configurations of pouch cells to analyze the individual effects of ALD coating on anode and cathode electroactive materials. Our extensive testing matrix included long-term cycling, fast discharge, fast charge, leakage current, and high voltage tests. While at lower C-rates (<~1C), the influence of Al 2 O 3 coatings on cell performance is not significant. Fast charging conditions reveal that the anode ALD coating significantly enhances performance via a passivating effect, while on the cathode, it is detrimental, potentially due to increased resistance of the thin interfacial layer formed during the ALD processing. Leakage current and high-voltage tests show that the application of ALD coatings on either anode or cathode effectively minimizes side reactions at the electrode-electrolyte interface. Additionally, ALD coatings significantly mitigate concentrated and localized lithium plating on the anodes. These insights provide a valuable understanding of the potential of ALD technologies in LIB manufacturing to tailor cell performance, paving the way for safer, more efficient, and cost-effective battery solutions.

25 ENERGY STORAGE↗

Removal of impurity Metals as Phosphates from Lithium-ion Battery leachates

Recovery of critical materials from end-of life (EOL) lithium-ion batteries (LIB) is gaining interest as demands for materials grows. Hydrometallurgical processes start with an intermediate product known as black mass which contains critical materials of interest (Co, Ni, Li, and graphite) as well as impurities such as Cu, Al, and Fe. These impurities are deleterious to downstream separation processes, as well as impact functionality of the final products. Here, these impurities effectively compete with most solvent extraction (SX) and metal recovery processes to diminish the overall yields of the desired materials. In this work, a process flowsheet is presented where a previously reported electrochemical leaching (ECL) process is followed by selective precipitation using diammonium hydrogen phosphate (DAP) to remove Cu, Al, and Fe from LIB leachate solutions. The electrochemical leach process removes Cu and produces a pH-adjusted leachate, ca. pH 2, without requiring an extra Cu extraction step. The addition of the precipitant DAP to leachate by slightly adjusting the pH to 3–4 at 45 °C, precipitates 95–99% of Al and Fe as their phosphates and the leachate retains >95% of Co, Ni and Li. After the filtration of phosphate impurities, the solution is ready for further processing, such as SX. As an unexpected result from the leachate processing, 20–30% of the Ni and Co co-crystalize as the double salt after cooling to room temperature, which could provide a shorter route to their recovery.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Decomposition of PVDF to delaminate cathode materials from end-of-life lithium-ion battery cathodes

The growing demand of electric vehicles and rapid consumption of rechargeable lithium-ion batteries (LIBs) require recycling of spent cathode active materials (CAMs) to reduce hazardous wastes and supply raw materials to LIB production. To separate CAMs from the cathode, direct calcination of polyvinylidene fluoride (PVDF) binder is widely applied, which leads to high energy consumption and release of toxic hydrogen fluoride. It is desirable to have an environmentally friendly and effective alternative to traditional direct calcination. In this study, five lithium salts, LiOAc (lithium acetate), LiNO 3 , LiCl, Li 2 CO 3 , and Li 2 SO 4 , were deployed and compared for their performance in recycling CAMs. A peel-off efficiency of up to 98.5% was achieved at a LiOAc to LiNO 3 molar ratio of 3:2, salt to cathode mass ratio of 10:1, and temperature of 300 °C at a holding time of 30 min. This system avoids corrosive chemicals and minimizes particle agglomeration of recycled products. Compared with sodium salt systems (NaOAc-NaNO 3 ) or direct calcination, the LiOAc-LiNO 3 system prevented high reaction temperature or further lithium loss and minimized crystal structure and morphological changes. In conclusion, a decomposition mechanism of PVDF through adsorption of HF and fluorine substitution was proposed.

25 ENERGY STORAGE↗

An epitaxial surface heterostructure anchoring approach for high-performance Ni-rich layered cathodes

Nickel-rich (Ni≥90%) layered oxides materials have emerged as a promising candidate for next-generation high-energy-density lithium-ion batteries (LIBs). However, their widespread application is hindered by structural fatigue and lattice oxygen loss. In this work, an epitaxial surface rock-salt nanolayer is successfully developed on the LiNi 0.9 Co 0.1 O 2 sub-surface via heteroatom anchoring utilizing high-valence element molybdenum modification. This in-situ formed conformal buffer phase with a thickness of 1.2nm effectively suppresses the continuous interphase side-reactions, and thus maintains the excellent structure integrity at high voltage. Furthermore, theoretical calculations indicate that the lattice oxygen reversibility in the anion framework of the optimized sample is obviously enhanced due to the higher content of O 2p states near the Fermi level than that of the pristine one. Meanwhile, the stronger Mo–O bond further reduces cell volume alteration, which improves the bulk structure stability of modified materials. Besides, the detailed charge compensation mechanism suggests that the average oxidation state of Ni is reduced, which induces more active Li + participating in the redox reactions, boosting the cell energy density. As a result, the uniquely designed cathode materials exhibit an extraordinary discharge capacity of 245.4 mAh g −1 at 0.1 C, remarkable rate performance of 169.3 mAh g −1 at 10 C at 4.5V, and a high capacity retention of 70.5% after 1000 cycles in full cells at a high cut-off voltage of 4.4V. Further, this strategy provides an valuable insight into constructing distinctive heterostructure on high-performance Ni-rich layered cathodes for LIBs.

25 ENERGY STORAGE↗

Failure analysis and design principles of silicon-based lithium-ion batteries using micron-sized porous silicon/carbon composite

Significant progresses have been made to overcome the fundamental challenges in silicon (Si)-based lithium-ion batteries (LIBs). However, much less work have been reported on the design and failure analysis these batteries for practical applications. In this work, we analyzed various cell design parameters affecting the performance of pouch cells using micron-sized porous Si with nano-pore structure and coated by pitch-carbon (p-Si/C). The correlation among particle level, electrode level, and cell level properties, especially the effect of electrode density on the volumetric capacity density of Si anode and full batteries have been systematically investigated. It is found that the corrosion of p-Si/C particle surface is the main failure mechanisms on the eventual capacity loss, while Li plating on anode electrode surface is the main reason for the fast capacity loss in later stage of cycling. The volumetric capacity of Si anode highly depends on both electrode density and the Si content. Moreover, the prelithiation of Si anodes is found to increase energy density while decreasing cycle life of Si-based full cells. Finally, the pathways and strategies for adoption of micron-sized p-Si/C anodes in LIBs have been proposed for their practical applications.

25 ENERGY STORAGE↗

Direct recycling of spent nickel-rich cathodes in reciprocal ternary molten salts

Lithium-ion batteries (LIBs) have revolutionized portable electronics and electric vehicles (EVs), but the growing accumulation of end-of-life (EOL) batteries poses environmental challenges. Recycling high-value cathodes from EOL LIBs can minimize waste and reduce the need for mining critical minerals. Here, this study focuses on the direct recycling of Ni-rich cathodes, particularly lithium-manganese-cobalt-oxide (NMC) 622 in a “reciprocal ternary molten salts (RTMS)" system. The ionothermal relithiation in the RTMS system successfully restores the layered structure, lithium content, and electrochemical performance of the NMC 622 cathode, comparable to the pristine material. The cost analysis reveals that cathode regeneration through ionothermal relithiation is more economical than virgin production or conventional recycling methods.

25 ENERGY STORAGE↗

Enabling fast discharge of Li-ion batteries via electrolyte formulations for urban air mobility applications

High-power discharge requirements are critical for lithium-ion batteries (LIBs) used in electric Vertical Takeoff and Landing (eVTOL) vehicles that are increasingly considered in urban mobility. This investigation places a particular emphasis on understanding the impact of electrolytes on discharge processes and rate capability. We aim to compare the discharge behavior of LiBs using a conventional electrolyte (Gen 2: 1.2 M LiPF 6 in EC:EMC) and the dual salt LiTFSI-LiBOB-based electrolyte. Here we carefully examine the profiles of charging and discharging, the behavior during extended cycles, impedance spectroscopy results, and the characteristics of the electrode surface. Our research findings demonstrate the complex relationship between the composition of electrolytes and the specific high-power discharge requirements of electric vertical takeoff and landing (eVTOL) systems. This research highlights the importance of customizing electrolyte compositions to optimize energy storage density while simultaneously enabling higher power extraction to enhance performance in short-range electric aviation.

25 ENERGY STORAGE↗

Coal-derived carbon anodes for lithium-ion batteries: Development, challenges, and prospects

Lithium-ion battery (LIB) development has increased rapidly, requiring low-cost anode materials with a high capacity, high-rate performance, and stable lifespan. Carbon-based anodes possess various exceptional morphologies and structures, making them promising candidates for meeting the technical demands; however, conventional synthetic carbon anode processes need expensive feedstocks that increase anode cost and limit commercialization. Coal, the most affordable and abundant carbon resource, has attracted increasing attention as the primary feedstock for producing high-value carbon anode materials. This article reviews the lithium storage mechanisms, characteristics, and productions of some high-valuable carbon anode materials for LIBs from coal and coal derivatives. The high-value carbon anode materials reviewed in this article are graphite, graphene, mesophase microbeads (MCMB), carbon fiber, and hard carbons. Furthermore, the remaining challenges and prospects of using coal-derived carbon materials to create high-performance and low-cost lithium-ion batteries are also discussed.

25 ENERGY STORAGE↗

Fast-charging lithium-ion batteries: Synergy of carbon nanotubes and laser ablation

Advancing lithium-ion battery (LiB) technology to achieve 10–15-min extreme fast charging (XFC) while maintaining high energy density and longevity poses a significant challenge. Addressing Li-plating is crucial, as it depletes useable Li, causing deterioration and safety issues. Here, this study explores a holistic approach incorporating Single-Wall Carbon Nanotubes (SWCNTs) and Laser Ablation (LA) to mitigate Li-plating while maintaining high charge acceptance under 10–15-min XFC. SWCNTs enhance the electrical conductivity and mechanical integrity of the positive electrode (PE), reducing overall cell overpotential at high charging rates. Concurrently, LA is applied to negative electrodes (NE) to reduce tortuosity of ion-diffusion pathways and increase surface wettability, improving Li-ion transport. Combining SWCNTs in the PE and LA on the NE, our experimental findings demonstrate a significant reduction in Li-plating and maintained high charge acceptance of ~84.33 % after 800 5C (12 min) charge cycles for cells having PE with ~3.3 mAh cm –2 and NE with 3.9 mAh cm –2 loadings. This study highlights the potential of combining SWCNTs and LA to address Li-plating in LiBs and opens new avenues for designing battery systems capable of achieving 10–15-min XFC.

24 POWER TRANSMISSION AND DISTRIBUTION↗

Assessing the coating implications of slurry formulations in NCMA and LFMP blend cathodes for lithium-ion batteries

This paper investigates the implications of slurry formulations and electrode processing on the performance of lithium-ion battery (LIB) cathodes, focusing on Nickel Cobalt Manganese Aluminum (NCMA) and Lithium Ferro Manganese Phosphate (LFMP) blends. Through a comprehensive examination of electrode processing steps, from material selection to coating application, we elucidate the critical role of processing parameters in shaping electrode morphology and electrochemical behavior. Rheological studies reveal the influence of slurry composition on viscosity and flow behavior, highlighting the importance of achieving optimal rheological properties for uniform coating deposition. Electrochemical characterization, including cyclic voltammetry and rate capability tests, unveils the electrochemical behavior of NCMA, LFMP, and their blend, showcasing the synergistic effects of material blending on battery performance. In conclusion, our findings underscore the intricate relationship between slurry formulation, electrode processing, and LIB performance, offering valuable insights for the design and optimization of high-performance electrode materials for next-generation batteries.

25 ENERGY STORAGE↗

Upcycling Polycrystalline LiNi1/3Mn1/3Co1/3O2 to High-Performance Large-Grained LiNi0.6Mn0.2Co0.2O2 via Simplified Polyol-Mediated Recycling

The escalating demand for lithium-ion batteries (LIBs) necessitates advanced recycling strategies that can address both resource scarcity and environmental impact. While conventional hydrometallurgy shows promise, it is challenged by complexity, impurity management, and environmental footprint. Here, we report a strategic polyol-metallurgy recycling process that efficiently transforms spent polycrystalline LiNi1/3Mn1/3Co1/3O2 (NMC111) into high-performance large-grained LiNi0.6Mn0.2Co0.2O2 (NMC622), offering dual benefits of compositional upcycling and morphology upgradation. Our approach leverages a polyol system with meticulous control over nickel salt addition and the precipitation process. This yields upcycled cathode materials possessing excellent structural integrity, well-defined large-grained particles (5-10?..mu..m), and robust electrochemical performance, including a specific capacity of ~182 mAh g-1 at C/10 and 88.0% capacity retention after 100 cycles. This facile and multifunctional process provides an environmental-friendly pathway for advanced cathode recycling, significantly contributing to a circular economy for LIBs through precise control over critical material attributes.

25 ENERGY STORAGE↗

Battery anode design: From 1D nanostructure to 3D nanoarchitecture – Enabling next-generation energy storage technology

Recently, many studies have reported the efficacy of 1D silicon nanostructures as anode materials (mostly nanowires) due to their large surface to volume ratio which could be an advantage in terms of charging kinetics. Anode design is a crucial factor for the further development of lithium-ion battery (LIB) technology, especially in terms of achieving the high charging rate performance, as typically needed in electric vehicles (EV). 3D nanostructures have been identified as the key to dramatically enhanced charging rate of LIB, in addition to the change of materials (from carbon-based anode to silicon-based). However, existing fabrication methodologies for 3D nanostructures are inherently expensive – using advanced lithography techniques or other nanopatterning methodologies, as well as using additive manufacturing approaches. Electrospinning (as an integrated additive manufacturing methodology) may be used to produce low-cost 3D-printed fiber structures. Here, in the present study, we demonstrate the groundwork in this field of research in the past 3–4 years, which would allow the extension of this special additive manufacturing approach to reach nanoscale 3D-printed fiber structures more economically and with scalability for manufacturing. This would pave the way to achieve the order of magnitude increase in battery charging rate as needed to realize the vision of the electrification of mobility/transportation.

25 ENERGY STORAGE↗

A conformal heat-drying direct ink writing 3D printing for high-performance lithium-ion batteries

High areal capacity electrodes hold great potential for high-energy density lithium-ion batteries (LIBs), but their poor electrochemical kinetics limit their power density. Here, in this study, high areal capacity 3D-structured LiNi 0.8 Mn 0.1 Co 0.1 O 2 cathodes (4.3 mAh cm -2 ) are prepared via 3D printing with a manner of direct ink writing. The electrodes had an enlarged electrode–electrolyte contact area, shortened diffusion pathway, and reduced intercalation-induced stress, thereby delivering enhanced rate capability and cyclability in LIBs, which is 143.6 mAh g -1 at 3C and a 60.2 % capacity retention over 800 cycles at 1C. Moreover, at electrode level, the 3D-NMC exhibits an energy and power densities of 313.1 Wh kg -1 and 657.9 W kg -1 , respectively. Furthermore, the theoretical calculation suggests that reducing the gap width will be highly beneficial to the energy and power densities. This work establishes a milestone in understanding the cycling effect on the electrode local structure, including the void area and the LiNi 0.8 Mn 0.1 Co 0.1 O 2 region, which confirms the effectiveness of 3D printing for electrode preparation.

25 ENERGY STORAGE↗

Preparation and electrochemical properties of high-entropy oxide Li x (CrMnCoNiZn) 3-x O 4

High-entropy oxides (HEOs) have gained significant attention as anode materials for lithium-ion batteries (LIBs) due to their high theoretical specific capacity, synergistic effects of constituent elements, and enhanced structural stability induced by high entropy. Here, this study investigates the electrochemical properties of a novel series of HEOs, Li x (CrMnCoNiZn) 3-x O 4 , synthesized via the sol-gel method. As lithium content increases, the electrochemical lithium storage performance of the HEOs improves, attributed to the rise in high-valence states and oxygen vacancies. The high valence state of elements facilitates greater electron transfer, enhancing the specific capacity during lithium insertion. Additionally, a higher concentration of oxygen vacancies boosts ionic conductivity and lithium ion diffusion kinetics, leading to superior electrochemical performance. Among the synthesized materials, Li 0.11 (CrMnCoNiZn) 2.89 O 4 exhibited the best performance, delivering a discharge capacity of 365 mAh·g −1 after 100 cycles at 100 mA·g −1 , 257 mAh·g −1 after 1000 cycles at 1 A·g −1 , and a rate capacity of 196 mAh·g −1 at 2 A·g −1 . The Li + diffusion coefficient reached 2.78 × 10 −15 cm 2 ·s −1 . This work not only deepens the understanding of HEOs' electrochemical behavior in LIBs but also provides insights into the impact of lithium ion substitution on their performance.

25 ENERGY STORAGE↗