Strategies for Controlling or Releasing the Influence Due to the Volume Expansion of Silicon inside Si−C Composite Anode for High-Performance Lithium-Ion Batteries

Currently, silicon is considered among the foremost promising anode materials, due to its high capacity, abundant reserves, environmental friendliness, and low working potential. However, the huge volume changes in silicon anode materials can pulverize the material particles and result in the shedding of active materials and the continual rupturing of the solid electrolyte interface film, leading to a short cycle life and rapid capacity decay. Therefore, the practical application of silicon anode materials is hindered. However, carbon recombination may remedy this defect. In silicon/carbon composite anode materials, silicon provides ultra-high capacity, and carbon is used as a buffer, to relieve the volume expansion of silicon; thus, increasing the use of silicon-based anode materials. To ensure the future utilization of silicon as an anode material in lithium-ion batteries, this review considers the dampening effect on the volume expansion of silicon particles by the formation of carbon layers, cavities, and chemical bonds. Silicon-carbon composites are classified herein as coated core-shell structure, hollow core-shell structure, porous structure, and embedded structure. The above structures can adequately accommodate the Si volume expansion, buffer the mechanical stress, and ameliorate the interface/surface stability, with the potential for performance enhancement. Finally, a perspective on future studies on Si−C anodes is suggested. In the future, the rational design of high-capacity Si−C anodes for better lithium-ion batteries will narrow the gap between theoretical research and practical applications.     

Effect of PVP Coating on LiMnBO3 Cathodes for Li-Ion Batteries

LiMnBO₃ is a potential cathode for Li-ion batteries, but it suffers from a low electrochemical activity. To improve the electrochemical performance of LiMnBO₃, the effect of polyvinyl pyrrolidone (PVP) as carbon additive was studied. Monoclinic LiMnBO₃/C and LiMnBO₃-MnO/C materials were obtained by a solid-state method at 500 °C. The structure, morphology and electrochemical behavior of these materials are characterized and compared. The results show that carbon additives and ball-milling dispersants affect the formation of impurities in the final products, but MnO is beneficial for the performance of LiMnBO₃. The sample of LiMnBO₃-MnO/C delivered a high capacity of 162.1 mAh g⁻¹ because the synergistic effect of the MnO/C composite and the suppression of the PVP coating on particle growth facilitates charge transfer and lithium–ion diffusion.     

Gallium-Indium-Tin Eutectic as a Self-Healing Room-Temperature Liquid Metal Anode for High-Capacity Lithium-Ion Batteries

Owing to their intrinsic properties, such as deformability, high electrical conductivity, and superior electrochemical performance, room-temperature liquid metals and liquid metal alloys have attracted the attention of researchers for a wide variety of applications, including portable and large-scale energy storage applications. In this study, novel gallium-indium-tin eutectic (EGaInSn) room-temperature liquid metal nanoparticles synthesized using a facile and scalable probe-ultrasonication method were used as anode material in lithium-ion batteries. The morphology, geometry, and self-healing properties of the synthesized room-temperature liquid metal nanoparticles were characterized using scanning electron microscopy (SEM) and transmission electron microscopy (TEM) with energy-dispersive X-ray spectroscopy (SEM/EDS and TEM/EDS). The synthesized room-temperature liquid metal nanoparticles delivered a specific capacity of 474 mAh g^–1 and retained 77% of the stable reversible capacity after 500 galvanostatic charge-discharge cycles at a constant current density of 0.1 A g^–1. The high theoretical specific capacity, combined with its self-healing and fluidic features, make EGaInSn room-temperature liquid metal nanoparticles a potential anode material for large-scale energy storage applications.     

Recent Progress in Advanced Materials for Lithium Ion Batteries

The development and commercialization of lithium ion batteries is rooted in material discovery. Promising new materials with high energy density are required for achieving the goal toward alternative forms of transportation. Over the past decade, significant progress and effort has been made in developing the new generation of Li-ion battery materials. In the review, I will focus on the recent advance of tin- and silicon-based anode materials. Additionally, new polyoxyanion cathodes, such as phosphates and silicates as cathode materials, will also be discussed.     

Sustainability Analysis of Processes to Recycle Discharged Lithium-Ion Batteries,Based on the ESCAPE Approach

There are several recycling methods to treat discharged lithium-ion batteries, mostly based on pyrometallurgical and hydrometallurgical approaches. Some of them are promising, showing high recovery efficiency (over 90%) of strategic metals such as lithium, cobalt, and nickel. However, technological efficiency must also consider the processes sustainability in terms of environmental impact. In this study, some recycling processes of spent lithium-ion batteries were considered, and their sustainability was evaluated based on the ESCAPE “Evaluation of Sustainability of material substitution using CArbon footPrint by a simplifiEd approach” approach, which is a screening tool preliminary to the Life Cycle Assessment (LCA). The work specifically focuses on cobalt recovery comparing the sustainability of using inorganic or organic acid for the leaching of waste derived from lithium-ion batteries. Based on the possibility to compare different processes, for the first time, some considerations about technologies optimization have been done, allowing proposing strategies able to save chemicals. In addition, the energy mix of each country, to generate electricity has been considered, showing its influence on the sustainability evaluation. This allows distinguishing the countries using more low-carbon sources (nuclear and renewables) for a share of the electricity mix, where the recycling processes result more sustainable. Finally, this outcome is reflected by another indicator, the eco-cost from the virtual pollution model 99′ proposed by Vogtländer, which integrates the monetary estimation of carbon footprint.     

Electrochemical Properties of Multilayered Sn/TiNi Shape-Memory-Alloy Thin-Film Electrodes for High-Performance Anodes in Li-Ion Batteries

Sn is a promising candidate anode material with a high theoretical capacity (994 mAh/g). However, the drastic structural changes of Sn particles caused by their pulverization and aggregation during charge–discharge cycling reduce their capacity over time. To overcome this, a TiNi shape memory alloy (SMA) was introduced as a buffer matrix. Sn/TiNi SMA multilayer thin films were deposited on Cu foil using a DC magnetron sputtering system. When the TiNi alloy was employed at the bottom of a Sn thin film, it did not adequately buffer the volume changes and internal stress of Sn, and stress absorption was not evident. However, an electrode with an additional top layer of room-temperature-deposition TiNi (TiNi(RT)) lost capacity much more slowly than the Sn or Sn/TiNi electrodes, retaining 50% capacity up to 40 cycles. Moreover, the charge-transfer resistance decreased from 318.1 Ω after one cycle to 246.1 Ω after twenty. The improved cycle performance indicates that the TiNi(RT) and TiNi-alloy thin films overall held the Sn thin film. The structure was changed so that Li and Sn reacted well; the stress-absorption effect was observed in the TiNi SMA thin films.     

Holographic patterning of high-performance on-chip 3D lithium-ion microbatteries

As sensors, wireless communication devices, personal health monitoring systems, and autonomous microelectromechanical systems (MEMS) become distributed and smaller, there is an increasing demand for miniaturized integrated power sources. Although thin-film batteries are well-suited for on-chip integration, their energy and power per unit area are limited. Three-dimensional electrode designs have potential to offer much greater power and energy per unit area; however, efforts to date to realize 3D microbatteries have led to prototypes with solid electrodes (and therefore low power) or mesostructured electrodes not compatible with manufacturing or on-chip integration. Here, we demonstrate an on-chip compatible method to fabricate high energy density (6.5 μWh cm⁻²⋅μm⁻¹) 3D mesostructured Li-ion microbatteries based on LiMnO₂ cathodes, and NiSn anodes that possess supercapacitor-like power (3,600 μW cm⁻²⋅μm⁻¹ peak). The mesostructured electrodes are fabricated by combining 3D holographic lithography with conventional photolithography, enabling deterministic control of both the internal electrode mesostructure and the spatial distribution of the electrodes on the substrate. The resultant full cells exhibit impressive performances, for example a conventional light-emitting diode (LED) is driven with a 500-μA peak current (600-C discharge) from a 10-μm-thick microbattery with an area of 4 mm² for 200 cycles with only 12% capacity fade. A combined experimental and modeling study where the structural parameters of the battery are modulated illustrates the unique design flexibility enabled by 3D holographic lithography and provides guidance for optimization for a given application.Microscale devices typically use power supplied off-chip because of difficulties in miniaturizing energy storage technologies (1, 2). However, a miniaturized on-chip battery would be highly desirable for applications including autonomous microelectromechanical systems (MEMS)-based actuators, microscale wireless sensors, distributed monitors, and portable and implantable medical devices (3–8). For many of the applications, high energy density, high power density (charge and/or discharge), or some combination of high energy and power densities is required, all characteristics which can be difficult to achieve in a microbattery due to size and footprint restrictions, and process compatibilities with the other steps required for device fabrication. Although 2D thin-film microbatteries (typical thickness of a few micrometers) can deliver high power, they require large (often cm²) footprints to provide reasonable energies (9). Making the electrodes thicker boosts the theoretical areal energy density but the resultant increases in electron and ion diffusion lengths reduce the effective power and energy densities. Efforts to improve microbattery performance have focused on increasing the electrode surface area and active material loading in the third dimension. Electrodes based on high-aspect-ratio micropillar structures, realized via methods including electrodeposition, polymer pyrolysis, and vapor deposition techniques, have been demonstrated (10–14). Despite the improved energy density compared with 2D batteries, because the micropillar electrodes are solid, the power and effective energy density is still limited due to the resultant long ion and electron diffusion pathways. Mesostructured 3D electrodes derived from nanowires or nanotubes have potential for achieving high energy and power densities, but difficulties in synthesis and full-cell assembly have limited these electrodes to half-cell demonstrations (15–18).As we demonstrated via a colloidal templating strategy (19–21), electrodes consisting of a layer of electrolytically active materials directly grown on a mesostructured 3D porous current collector can offer both high energy and power densities by providing efficient electron pathways, short solid-state ion diffusion lengths, and a pore network for Li-ion transport. Unlike for a micropillar, all of the major internal resistances of the microbattery can be simultaneously minimized. The colloidally templated 3D mesostructured electrodes were first fabricated in a half-cell configuration, and the resulting electrode indeed delivered supercapacitor-like power (e.g., 40% energy discharge in 3 s) while maintaining battery-like energy (19). We subsequently fabricated a microbattery (full cell) with an unprecedented 2,000× increase in power compared with previous microbatteries (22) via a similar approach. However, colloidally templated microbatteries contain a number of serious limitations. From a purely practical standpoint, a fabrication approach that involves growth of a colloidal crystal from a colloidal suspension on a substrate is unlikely to be acceptable in a manufacturing environment, because it is slow, and submicrometer colloidal particles are generally unwelcome in a microfabrication facility. The mesostructure and connectivity of the colloidally templated system is severely restricted by the close-packed particles, allowing almost no freedom to alter the structure of a unit cell. Finally, all colloidal crystals contain defects (e.g., cracks), which end up in the final electrode structure as solid elements (the inverse of a crack). These solid elements locally limit ion transport and make capacity matching between anode and cathode difficult, which may in part be why the cycle life of the colloidally templated microbattery was low. In contrast with colloidal assembly and other 3D fabrication techniques such as direct laser (ink) writing (which produces 3D structures in a point-to-point or layer-by-layer fashion) (23, 24), 3D holographic lithography generates periodic, defect-free features (50∼1,000 nm) in a one-step exposure (∼ seconds) over an area that is linearly proportional to the beam size. It can create a variety of complex 3D structures by varying the beam patterns and exposure conditions. Although accurate control on the interfering optical beams is required to construct 3D holographic lithography, recent advances have significantly simplified the required optics, enabling creation of structures via a single incident beam and standard photoresist processing, making it highly scalable and compatible with microfabrication (25, 26).Here, we describe a flexible and deterministic 3D fabrication route which combines 3D holographic lithography with conventional photolithography to create microbatteries with good cycle lives, and high power and energy densities using complementary metal-oxide–semiconductor (CMOS) and microfluidic device-compatible processing steps. The holographic lithography creates a defined periodically mesostructured 3D lattice, whereas the conventional photolithography defines a set of 2D solid structures that divide the 3D lattice into an interdigitated pattern. The combination of these two lithography processes provides comprehensive control of the electrode mesostructure and spatial arrangement, enabling formation of flat-sided and topped 3D current collectors with independently deposited high-quality cathode and anode active materials. The resultant full cells exhibit energy and power densities up to 6.5 μWh cm⁻²⋅μm⁻¹ (energy-optimized electrode spacing) and 3,600 μW cm⁻²⋅μm⁻¹ (power-optimized electrode spacing), with less than 5% cell-to-cell distribution. The cells retain at least 80% of the initial capacity after cycling 100 times at various rates, and 88% of the initial capacity after driving a light-emitting diode (LED) for 200 cycles. The capacity for fast charging and discharging endues the microbattery with rather unexpected capabilities for a battery which is only 2 mm on a side and ∼10 µm thick, for example the battery could repeatedly (>200 cycles) drive a conventional LED with a 600-C peak current (∼0.5 mA). A combined experimental and modeling study where the structural parameters of the battery are modulated illustrates the unique design flexibility enabled by 3D holographic lithography and provides guidance for optimization for a given application.     

Insight into a Nitrogen-Doping Mechanism in a Hard-Carbon-Microsphere Anode Material for the Long-Term Cycling of Potassium-Ion Batteries

To investigate the alternatives to lithium-ion batteries, potassium-ion batteries have attracted considerable interest due to the cost-efficiency of potassium resources and the relatively lower standard redox potential of K⁺/K. Among various alternative anode materials, hard carbon has the advantages of extensive resources, low cost, and environmental protection. In the present study, we synthesize a nitrogen-doping hard-carbon-microsphere (N-SHC) material as an anode for potassium-ion batteries. N-SHC delivers a high reversible capacity of 248 mAh g⁻¹ and a promoted rate performance (93 mAh g⁻¹ at 2 A g⁻¹). Additionally, the nitrogen-doping N-SHC material also exhibits superior cycling long-term stability, where the N-SHC electrode maintains a high reversible capacity at 200 mAh g⁻¹ with a capacity retention of 81% after 600 cycles. DFT calculations assess the change in K ions’ absorption energy and diffusion barriers at different N-doping effects. Compared with an original hard-carbon material, pyridinic-N and pyrrolic-N defects introduced by N-doping display a positive effect on both K ions’ absorption and diffusion.     

Organic Anode Materials for Lithium-Ion Batteries: Recent Progress and Challenges

In the search for novel anode materials for lithium-ion batteries (LIBs), organic electrode materials have recently attracted substantial attention and seem to be the next preferred candidates for use as high-performance anode materials in rechargeable LIBs due to their low cost, high theoretical capacity, structural diversity, environmental friendliness, and facile synthesis. Up to now, the electrochemical properties of numerous organic compounds with different functional groups (carbonyl, azo, sulfur, imine, etc.) have been thoroughly explored as anode materials for LIBs, dividing organic anode materials into four main classes: organic carbonyl compounds, covalent organic frameworks (COFs), metal-organic frameworks (MOFs), and organic compounds with nitrogen-containing groups. In this review, an overview of the recent progress in organic anodes is provided. The electrochemical performances of different organic anode materials are compared, revealing the advantages and disadvantages of each class of organic materials in both research and commercial applications. Afterward, the practical applications of some organic anode materials in full cells of LIBs are provided. Finally, some techniques to address significant issues, such as poor electronic conductivity, low discharge voltage, and undesired dissolution of active organic anode material into typical organic electrolytes, are discussed. This paper will guide the study of more efficient organic compounds that can be employed as high-performance anode materials in LIBs.     

Nano-Graphite Prepared by Rapid Pulverization as Anode for Lithium-Ion Batteries

Reducing the particle size of active material is an effective solution to the poor rate performance of the lithium-ion battery. In this study, we proposed a facile strategy for the preparation of nano-graphite as an anode for a lithium-ion battery via the rapid mechanical pulverization method. It is the first time that diamond particle was selected as the medium to achieve high preparation efficiency and low energy consumption. The as-prepared nano-graphite with the size from 10 to 300 nm displays an intact structure and high specific surface area. The introduced oxygen atoms increased the wettability of nano-graphite electrode and lowered its polarization. The nano-graphite prepared from three hours of grinding shows an excellent reversible capacity of 191 mAh g⁻¹, at a rate of 5 C, after 480 cycles, along with an increase of 86% in capacity, at 1 C, in comparison with pristine graphite. The highlight of this strategy is to optimize the current preparation method. The good electrochemical performance comes from the combined effect of nano-scale particle size, large specific surface area, and continuous mesopores.     

Biomass Porous Carbons Derived from Banana Peel Waste as Sustainable Anodes for Lithium-Ion Batteries

Disordered carbons derived from banana peel waste (BPW) were successfully obtained by employing a simple one-step activation/carbonization method. Different instrumental techniques were used to characterize the structural, morphological, and textural properties of the materials, including X-ray diffraction, thermogravimetric analysis, porosimetry and scanning electron microscopy with energy-dispersive X-ray spectroscopy. The chemical activation with different porogens (zinc chloride, potassium hydroxide and phosphoric acid) could be used to develop functional carbonaceous structures with high specific surface areas and significant quantities of pores. The BPW@H₃PO₄ carbon exhibited a high specific surface area (815 m² g⁻¹), chemical stability and good conductivity for use as an anode in lithium-ion batteries. After 200 cycles, this carbon delivered a reversible capacity of 272 mAh g⁻¹ at 0.2 C, showing a notable retention capacity and good cycling performance even at high current densities, demonstrating its effectiveness and sustainability as an anode material for high-energy applications in Li-ion batteries.     

A Hierarchical SnO2@Ni6MnO8 Composite for High-Capacity Lithium-Ion Batteries

Semiconductor-based composites are potential anodes for Li-ion batteries, owing to their high theoretical capacity and low cost. However, low stability induced by large volumetric change in cycling restricts the applications of such composites. Here, a hierarchical SnO₂@Ni₆MnO₈ composite comprising Ni₆MnO₈ nanoflakes growing on the surface of a three-dimensional (3D) SnO₂ is developed by a hydrothermal synthesis method, achieving good electrochemical performance as a Li-ion battery anode. The composite provides spaces to buffer volume expansion, its hierarchical profile benefits the fast transport of Li⁺ ions and electrons, and the Ni₆MnO₈ coating on SnO₂ improves conductivity. Compared to SnO₂, the Ni₆MnO₈ coating significantly enhances the discharge capacity and stability. The SnO₂@Ni₆MnO₈ anode displays 1030 mAh g⁻¹ at 0.1 A g⁻¹ and exhibits 800 mAh g⁻¹ under 0.5 A g⁻¹, along with high Coulombic efficiency of 95%. Furthermore, stable rate performance can be achieved, indicating promising applications.     

Al2O3-Coated Si-Alloy Prepared by Atomic Layer Deposition as Anodes for Lithium-Ion Batteries

Silicon-based anodes can increase the energy density of Li-ion batteries (LIBs) owing to their large weights and volumetric capacities. However, repeated charging and discharging can rapidly deteriorate the electrochemical properties because of a large volume change in the electrode. In this study, a commercial Fe-Si powder was coated with Al₂O₃ layers of different thicknesses via atomic layer deposition (ALD) to prevent the volume expansion of Si and suppress the formation of crack-induced solid electrolyte interfaces. The Al₂O₃ content was controlled by adjusting the trimethyl aluminum exposure time, and higher Al₂O₃ contents significantly improved the electrochemical properties. In 300 cycles, the capacity retention rate of a pouch full-cell containing the fabricated anodes increased from 69.8% to 72.3% and 79.1% depending on the Al₂O₃ content. The powder characterization and coin and pouch cell cycle evaluation results confirmed the formation of an Al₂O₃ layer on the powder surface. Furthermore, the expansion rate observed during the charging/discharging of the pouch cell indicated that the deposited layer suppressed the powder expansion and improved the cell stability. Thus, the performance of an LIB containing Si-alloy anodes can be improved by coating an ALD-synthesized protective Al₂O₃ layer.     

Flexible Porous Silicon/Carbon Fiber Anode for High−Performance Lithium−Ion Batteries

We demonstrate a cross−linked, 3D conductive network structure, porous silicon@carbon nanofiber (P−Si@CNF) anode by magnesium thermal reduction (MR) and the electrospinning methods. The P−Si thermally reduced from silica (SiO₂) preserved the monodisperse spheric morphology which can effectively achieve good dispersion in the carbon matrix. The mesoporous structure of P–Si and internal nanopores can effectively relieve the volume expansion to ensure the structure integrity, and its high specific surface area enhances the multi−position electrical contact with the carbon material to improve the conductivity. Additionally, the electrospun CNFs exhibited 3D conductive frameworks that provide pathways for rapid electron/ion diffusion. Through the structural design, key basic scientific problems such as electron/ion transport and the process of lithiation/delithiation can be solved to enhance the cyclic stability. As expected, the P−Si@CNFs showed a high capacity of 907.3 mAh g⁻¹ after 100 cycles at a current density of 100 mA g⁻¹ and excellent cycling performance, with 625.6 mAh g⁻¹ maintained even after 300 cycles. This work develops an alternative approach to solve the key problem of Si nanoparticles’ uneven dispersion in a carbon matrix.     

Enhanced Electrochemical Performance Promoted by Tin in Silica Anode Materials for Stable and High-Capacity Lithium-Ion Batteries

Although the silicon oxide (SiO₂) as an anode material shows potential and promise for lithium-ion batteries (LIBs), owing to its high capacity, low cost, abundance, and safety, severe capacity decay and sluggish charge transfer during the discharge–charge process has caused a serious challenge for available applications. Herein, a novel 3D porous silicon oxide@Pourous Carbon@Tin (SiO₂@Pc@Sn) composite anode material was firstly designed and synthesized by freeze-drying and thermal-melting self-assembly, in which SiO₂ microparticles were encapsulated in the porous carbon as well as Sn nanoballs being uniformly dispersed in the SiO₂@Pc-like sesame seeds, effectively constructing a robust and conductive 3D porous Jujube cake-like architecture that is beneficial for fast ion transfer and high structural stability. Such a SiO₂@Pc@Sn micro-nano hierarchical structure as a LIBs anode exhibits a large reversible specific capacity ~520 mAh·g⁻¹, initial coulombic efficiency (ICE) ~52%, outstanding rate capability, and excellent cycling stability over 100 cycles. Furthermore, the phase evolution and underlying electrochemical mechanism during the charge–discharge process were further uncovered by cyclic voltammetry (CV) investigation.     

Structural and Electrochemical Investigation during the First Charging Cycles of Silicon Microwire Array Anodes for High Capacity Lithium Ion Batteries

Silicon microwire arrays embedded in Cu present exceptional performance as anode material in Li ion batteries. The processes occurring during the first charging cycles of batteries with this anode are essential for good performance. This paper sheds light on the electrochemical and structural properties of the anodes during the first charging cycles. Scanning Electron Microscopy, X-ray diffractommetry, and fast Fourier transformation impedance spectroscopy are used for the characterization. It was found that crystalline phases with high Li content are obtained after the first lithiation cycle, while for the second lithiation just crystalline phases with less Li are observable, indicating that the lithiated wires become amorphous upon cycling. The formation of a solid electrolyte interface of around 250 nm during the first lithiation cycle is evidenced, and is considered a necessary component for the good cycling performance of the wires. Analog to voltammetric techniques, impedance spectroscopy is confirmed as a powerful tool to identify the formation of the different Si-Li phases.     

Short-Term Impact of AC Harmonics on Aging of NiMH Batteries for Grid Storage Applications

Batteries in energy storage systems are exposed to electrical noise, such as alternating current (AC) harmonics. While there have been many studies investigating whether Lithium-ion batteries are affected by AC harmonics, such studies on Nickel Metal Hydride (NiMH) batteries are scarce. In this study a 10 Ah, 12 V NiMH battery was tested with three different harmonic current frequency overlays during a single charge/discharge cycle: 50 Hz, 100 Hz, and 1000 Hz. No effect on battery internal temperature or gas pressure was found, indicating that NiMH battery aging is not affected by the tested harmonic AC frequencies. This can reduce the cost of energy storage systems, as no extra filters are needed to safeguard the batteries. Instead, the capacitive properties of the batteries give the possibility to use the battery bank itself as a high pass filter, further reducing system complexity and cost.     

Boosting Lithium Storage of a Metal-Organic Framework via Zinc Doping

Lithium-ion batteries (LIBs) as a predominant power source are widely used in large-scale energy storage fields. For the next-generation energy storage LIBs, it is primary to seek the high capacity and long lifespan electrode materials. Nickel and purified terephthalic acid-based MOF (Ni-PTA) with a series amounts of zinc dopant (0, 20, 50%) are successfully synthesized in this work and evaluated as anode materials for lithium-ion batteries. Among them, the 20% atom fraction Zn-doped Ni-PTA (Zn_0.2-Ni-PTA) exhibits a high specific capacity of 921.4 mA h g⁻¹ and 739.6 mA h g⁻¹ at different current densities of 100 and 500 mA g⁻¹ after 100 cycles. The optimized electrochemical performance of Zn_0.2-Ni-PTA can be attributed to its low charge transfer resistance and high lithium-ion diffusion rate resulting from expanded interplanar spacing after moderate Zn doping. Moreover, a full cell is fabricated based on the LiFePO₄ cathode and as-prepared MOF. The Zn_0.2-Ni-PTA shows a reversible specific capacity of 97.9 mA h g⁻¹ with 86.1% capacity retention (0.5 C) after 100 cycles, demonstrating the superior electrochemical performance of Zn_0.2-Ni-PTA anode as a promising candidate for practical lithium-ion batteries.     

A Multiphysics Peridynamic Model for Simulation of Fracture in Si Thin Films during Lithiation/Delithiation Cycles

Material failure is the main obstacle in fulfilling the potential of electrodes in lithium batteries. To date, different failure phenomena observed experimentally in various structures have become challenging to model in numerical simulations. Moreover, their mechanisms are not well understood. To fill the gap, here we develop a coupled chemo-mechanical model based on peridynamics, a particle method that is suitable for simulating spontaneous crack growth, to solve the fracture problems in silicon thin films due to lithiation/delithiation. The model solves mechanical and lithium diffusion problems, respectively, and uses a coupling technique to deal with the interaction between them. The numerical examples of different types of Si films show the advantage of the model in this category and well reproduce the fracture patterns observed in the experiments, demonstrating that it is a promising tool in simulating material failure in electrodes.     

Ga2Te3-Based Composite Anodes for High-Performance Sodium-Ion Batteries

Recently, metal chalcogenides have received considerable attention as prospective anode materials for sodium-ion batteries (SIBs) because of their high theoretical capacities based on their alloying or conversion reactions. Herein, we demonstrate a gallium(III) telluride (Ga₂Te₃)-based ternary composite (Ga₂Te₃–TiO₂–C) synthesized via a simple high-energy ball mill as a great candidate SIB anode material for the first time. The electrochemical performance, as well as the phase transition mechanism of Ga₂Te₃ during sodiation/desodiation, is investigated. Furthermore, the effect of C content on the performance of Ga₂Te₃–TiO₂–C is studied using various electrochemical analyses. As a result, Ga₂Te₃–TiO₂–C with an optimum carbon content of 10% (Ga₂Te₃–TiO₂–C(10%)) exhibited a specific capacity of 437 mAh·g⁻¹ after 300 cycles at 100 mA·g⁻¹ and a high-rate capability (capacity retention of 96% at 10 A·g⁻¹ relative to 0.1 A·g⁻¹). The good electrochemical properties of Ga₂Te₃–TiO₂–C(10%) benefited from the presence of the TiO₂–C hybrid buffering matrix, which improved the mechanical integrity and electrical conductivity of the electrode. This research opens a new direction for the improvement of high-performance advanced SIB anodes with a simple synthesis process.