Lithium Diffusion Research Articles

MoS2-C superlattice cathodes for conductive additive-free sulfide electrolyte-based all-solid-state lithium batteries

Sulfide electrolytes play a crucial role in the pursuit of high-performance all-solid-state lithium batteries (ASSLBs). However, most sulfide electrolytes have intrinsic narrow electrochemical stability windows, and decomposition reactions are thermodynamically favorable, especially contact with conductive additive. These ongoing side reactions accelerate sulfide electrolytes degradation, posing a significant threat to the cycling stability of ASSLBs. Herein, we propose an effective approach to address this challenge by designing a MoS2-C superlattice structure. This architecture, characterized by a layer-by-layer inter-stacking of MoS2 nanosheets and carbon layers, endows it with excellent electronic conductivity and enhanced lithium diffusion kinetics. Leveraging this superlattice, ASSLBs incorporating MoS2-C superlattice as the cathode without conductive additive exhibit a substantial improvement in electrochemical performance, ultimately achieving a conductive additive-free ASSLB. Remarkably, the conductive additive-free ASSLBs based on the MoS2-C superlattice demonstrates outstanding stability, enduring 300 cycles with a capacity retention of 96.8 % at a 1 C rate. This enhancement can be attributed to the improved charge transfer kinetics of MoS2-C superlattice and the effective suppression of side reactions between the sulfide electrolyte and conductive additive. Our study presents a promising design strategy to achieve high-rate performance and tackle long-term challenges in the application of sulfide electrolytes-based ASSLBs.

High-throughput investigation of stability and Li diffusion of doped solid electrolytes via neural network potential without configurational knowledge

Solid electrolytes hold substantial promise as vital components of all-solid-state batteries. Enhancing their performance necessitates simultaneous improvements in their stability and lithium conductivity. These properties can be calculated using first-principles simulations, provided that the crystal structure of the material and the diffusion pathway through the material are known. However, solid electrolytes typically incorporate dopants to enhance their properties, necessitating the optimization of the dopant configuration for the simulations. Yet, performing such calculations via the first-principles approach is so costly that existing approaches usually rely on predetermined dopant configurations informed by existing knowledge or are limited to systems doped with only a few atoms. The proposed method enables the optimization of the dopant configuration with the support of neural network potential (NNP). Our approach entails the use of molecular dynamics to analyze the diffusion after the optimization of the dopant configuration. The application of our approach to Li10\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${_{10}}$$\\end{document}MP2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${_{2}}$$\\end{document}S12-x\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${_{12-x}}$$\\end{document}Ox\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${_{x}}$$\\end{document} (M = Ge, Si, or Sn) reproduce the experimental results well. Furthermore, analysis of the lithium diffusion pathways suggests that the activation energy of diffusion undergoes a percolation transition. This study demonstrates the effectiveness of NNPs in the systematic exploration of solid electrolytes.

Damage-Tolerant and Self-Repairing Web-Like Borate Type Binder Enable Stable Operation of Efficient Si-Based Anodes.

Novel binder designs are shown to be fruitful in improving the electrochemical performance of silicon (Si)-based anodes. However, issues with mechanical damage from dramatic volume change and poor lithium-ion (Li+) diffusion kinetics in Si-based materials still need to be addressed. Herein, an aqueous self-repairing borate-type binder (SBG) with a web-like architecture and high ionic conductivity is designed for Si and SiO electrodes. The 3D web-like architecture of the SBG binder enables uniform stress distribution, while its self-repairing ability promotes effective stress dissipation and mechanical damage repair, thereby enhancing the damage tolerance of the electrode. The tetracoordinate boron ions ( ) in the SBG binder boosts the Li transportation kinetics of Si-based electrodes. Based on dynamic covalent and ionic conductive boronic ester bonds, the diverse requirements of the binder, including uniform stress distribution, self-repairing ability, and high ionic conductivity, can be met by simple components. Consequently, the proposed straightforward multifunction design strategy for binders based on dynamic boron chemistry provides valuable insights into fabricating high-performance Si-based anodes.

Enhancing performance of silicon/graphene composites by transition lattice interfaces constructed using plasma

The silicon-based (Si) anodes have not widely used due to their low conductivity and severe irreversible volume changes until now. Graphene (G) is considered a promising material for inhibiting volume expansion and enhancing conductivity of Si, a large amount of work has been exploring effective composite of graphene and silicon. A new SiG composite structure (PB-SiG-1) with transition lattice interface is provided by N plasma assisted technique in this work. The phase interface undergoes lattice changes on the atomic scale with silicon, oxygen, and carbon bonding in new chemical bonds (Si-O-C). More importantly, the lattice spacing of Si (111) increases from 0.31 nm to 0.325 nm due to the insertion of carbon or oxygen atom into the Si body, which promotes the diffusion kinetics of lithium ions. This PB-SiG-1 exhibits better electrochemical performance with reversible specific capacity of 2013.9 mAh g−1 after 100 cycles at 0.2 A g−1, high capacity retention of 98.53% and coulombic efficiency of 99.4%. The multiple advanced in situ methods reveal that the PB-SiG-1 not only has the ability to quickly transfer ions, electrons, and form stable SEI, but also has a low irreversible volume expansion of 33.1 %. This proves that the transition lattice interface endows PB-SiG-1 with isotropy characteristic of lithium diffusion, leading to dynamically stable electrodes during cycles. This work proposes a Si-C composite structure with transition lattice interface, which opens a new insight for volume expansion and lithium transmission in Si-C composite.

Phase Evolution of Multi-Metal Dichalcogenides With Conversion-Alloying Hybrid Mechanism for Superior Lithium Storage.

Traditional lithium-ion battery (LIB) anodes, whether intercalation-type like graphite or alloying-type like silicon, employing a single lithium storage mechanism, are often limited by modest capacity or substantial volume changes. Here, the kesterite multi-metal dichalcogenide (CZTSSe) is introduced as an anode material that harnesses a conversion-alloying hybrid lithium storage mechanism. Results unveil that during the charge-discharge processes, the CZTSSe undergoes a comprehensive phase evolution, transitioning from kesterite structure to multiple dominant phases of sulfides, selenides, metals, and alloys. The involvement of multi-components facilitates electron transport and mitigates swelling stress; meanwhile, it results in formation of abundant defects and heterojunctions, allowing for increased lithium storage active sites and reduced lithium diffusion barrier. The CZTSSe delivers a high specific capacity of up to 2266mA h g-1 at 0.1 A g-1; while, maintaining a stable output of 116mA h g-1 after 10000 cycles at 20 A g-1. It also demonstrates remarkable low-temperature performance, retaining 987mA h g-1 even after 600 cycles at -40°C. When employed in full cells, a high specific energy of 562Wh kg-1 is achieved, rivalling many state-of-the-art LIBs. This research offers valuable insights into the design of LIB electrodes leveraging multiple lithium storage mechanisms.

High-Performance Dendrite-Free Lithium Metal Anode Based on Metal-Organic Framework Glass.

The performance of lithium metal batteries is severely hampered by uncontrollable dendrite growth and volume change within the anode. This work addresses these obstacles by introducing a novel strategy: applying an isotropic and internal grain-boundary-free layer, specifically, a metal-organic framework (MOF) glass layer with nano-porosity onto the electrochemically plated lithium metal anode. Both ab initio and classical molecular dynamics simulations indicate that the MOF glass layer makes the lithium transport smooth and uniform via its internal monolithic and interfacial advantages. This MOF glass layer with the fast and more uniform lithium diffusion in the monolithic interior and its interface enables dendrite-free lithium plating and stripping through surface confinement effect and interfacial effect. When employed in symmetric batteries, the achieved Li metal anode can operate over 300h at 1mAcm-2. The full batteries matched with LiFePO4 exhibit high capacity (148mAhg-1), excellent rate performance (61mAhg-1 at 5C), and outstanding cycling stability (with capacity retention of ≈90% after 1000 cycles). The full batteries matched with high-voltage LiCoO2 also show superior performances. Therefore, the strategy of utilizing a MOF glass layer enables the development of high-performance lithium metal anodes.

Mo-doping modulated cationic vacancy in Zn3V2O8 with enhanced electrochemical performance for lithium-ion batteries

Given diverse redox reactions and abundant raw materials, Zn3V2O8 with high specific capacity is considered as a potential anode material for lithium-ion batteries. Same as other transition metal oxides, Zn3V2O8 suffers from infertile conductivity, sluggish ion diffusion and fast capacity loss derived from volume expansion during discharge/charge process, further hindering its application. In this work, a novel Mo doped Zn3V2O8 (Zn3V2-xMo5x/6O8) anode material with cationic vacancy (V vacancy) has been designed through a facile sol-gel method. It is found that a small Mo-doping amount has nearly no influence on the crystal structure, morphology and element valence states of Zn3V2O8. Mo doped Zn3V2O8 samples possess smaller charge transfer resistance and higher lithium ion diffusion coefficient. The results of electrochemical performance illustrate that Mo doped Zn3V2O8 can deliver higher reversible specific capacities and better rate capability compared with Zn3V2O8, which can be ascribed to the introduction of V vacancy. In particular, when Mo-doping amount is set as 0.03, the obtained Zn3V1.97Mo0.025O8 exhibits a reversible capacity of 481.1 mAh g−1 after 600 cycles at 1 A g−1. It is believed that this work could provide an effective and feasible strategy to construct high performance transition metal vanadate anode materials for lithium-ion batteries.

Effects of Ti4+ doping on electrochemical properties of LiNi0.815Co0.15Al0.035O2 cathode materials

The high nickel ternary cathode materials LiNi0.815Co0.15Al0.035O2 (NCA) have been widely used in Li-ion batteries due to their high energy density, low cost, and little environmental pollution. However, it suffers from rapid capacity degradation and poor charging rate. In this work, Ti4+ doping NCA cathode materials are prepared by the high-temperature solid-state method. The results show that 0.5%Ti-NCA has a lower cationic mixing degree and better cycling performance. The capacity retention rate of 100 cycles is 98.91% and 96.59% at current densities of 0.5 C and 1.0 C, respectively. The CV and EIS test results show that 0.5%Ti-NCA has lower polarization and higher lithium ion diffusion coefficient DLi+(8.43×10−14 cm2/S) after 100 cycles, while Pure-NCA only has 6.92×10−15 cm2/S, which effectively enhances the electrochemical properties of NCA cathode materials.

Li-ion storage chemistry of metal layers influences on metal oxides

A suitable current collector is a critical criterion for attaining high areal capacity in lithium batteries (LIBs). Here, we discover that the transition metal foam-type current collectors and their corresponding active materials upon a simple oxidation process, enable us to design a strategy for controlling the thickness of active materials toward achieving high areal capacity LIBs. Taking nickel foam (NiF) as a case study, we demonstrated that by calcining it in the air at different temperatures of 500 ℃, 600 ℃, 700 ℃, and 800 ℃, the electrodes exhibit distinct physical properties such as the thickness of active material layers, mechanical strength, and electrochemical properties including the rate capabilities, pseudocapacitive contribution, and lithium-ion diffusion. Ultimately, the optimized anode calcined at 700 °C (700-NiO@NiF) maintains a high reversible areal capacity of 7.6 mAh cm−2@0.4 mA cm−2, and 2.0 mAh cm−2 after 200 cycles@3.0 mA cm−2, We further verify that both cobalt foam and copper foam exhibited similar features like that of NiF by tuning their annealing temperatures, creating more opportunities for maximizing the areal capacity of LIBs.

Functionalized γ-Boehmite Covalent Grafting Modified Polyethylene for Lithium-Ion Battery Separator.

In the field of lithium-ion batteries, the challenges posed by the low melting point and inadequate wettability of conventional polyolefin separators have increased the focus on ceramic-coated separators. This study introduces a highly efficient and stable boehmite/polydopamine/polyethylene (AlOOH-PDA-PE) separator. It is crafted by covalently attaching functionalized nanosized boehmite (γ-AlOOH) whiskers onto polyethylene (PE) surfaces. The presence of a covalent bond increases the stability at the interface, while amino groups on the surface of the separator enhance the infiltration of the electrolyte and facilitate the diffusion of lithium ions. The PE-PDA-AlOOH separator, when used in lithium-ion batteries, achieves a discharge capacity of 126 mAh g-1 at 5 C and retains 97.1% capacity after 400 cycles, indicating superior cycling stability due to its covalently bonded ceramic surface. Thus, covalent interface modification is a promising strategy to prevent delamination of ceramic coatings in separators.

Mechanistic Understanding of Sieving Lithium Ions Using a Biobased Sorbent Technology for Sustainable Lithium Reclamation and Cleansing Brines.

Low-cost environmentally benign materials that can be produced in a large scale to extract lithium from brine resources could drive the lithium market toward a clean technology with high lithium recovery and production. Herein, we have investigated the utilization of a novel, environmentally benign, and low-cost biobased sorbent for the extraction of lithium from lithium-rich solutions. This biobased molecular sieving sorbent, iron(III)-tannate (Fe(III)-TA), belongs to a novel class of coordination polymer frameworks derived from a natural polyphenol-tannic acid (TA)-coordinated with iron(III) metal cations. Its lithium adsorption and kinetic isotherm studies conducted using lithium-rich aqueous solutions confirm the sorbent's dual function for lithium sieving via physisorption, chemisorption, and mass transfer diffusion processes. The adsorption equilibrium and kinetic isotherm models combined with the external and internal mass transfer diffusion models reveal a mechanistic pathway for lithium-ion adsorption. Aiding by forming a fluid film for external mass transfer diffusion of lithium ions, analytes adsorb onto the sorbent surface via physisorption and chemisorption followed by the internal mass transfer diffusion, occupying lithium ions in the sorbent's pores. The lithium adsorption efficiency studies conducted for brines with different concentrations of interference alkali and alkaline cations evidence that the sorbent's affinity for lithium ions strongly depends on the analyte concentration. The results evidence that the sorbent has the ability to lower the brine's salinity and significantly reduces the ratios of Mg/Li and Ca/Li by 4-fold and 10-fold, respectively, yielding lithium-rich solutions. Thus, implementing this innovative biobased sorbent technology as an add-in step into traditional lithium extraction and refining processes, one can design a cost-effective pathway to yield lithium-rich leachate by reducing the Mg/Li and Ca/Li ratio. Nonetheless, the present work demonstrates that Fe(III)-tannate is an effective multifunctional sorbent for sieving lithium from lithium-rich aqueous solutions as well as for desalinating brine resources to recover usable water. Thus, this biobased sorbent offers the possibility of effective application of lithium reclamation and remediation of brine, mitigating the environmental impact of brine discharge and large volume of freshwater usage for lithium extraction and refining.

Bifunctional effects of nitrogen-doped carbon quantum dots on CoS2/mesoporous carbon composites for high-performance lithium-ion batteries

Cobalt disulfide (CoS2) stands as a promising candidate for anode materials in lithium-ion batteries due to its high theoretical capacity, but it faces challenges associated with the shuttle effect of lithium polysulfide during cycling. To address these issues, zeolitic imidazolate framework (ZIF)-derived composites have been extensively explored because of distinct advantages such as the formation of nano-sized particles, heteroatom doping, and highly porous structures. However, ZIF-derived carbon supports primarily consist of ultra-micropores that can impede lithium-ion diffusion. Herein, we aimed to enhance cycling stability by introducing a nitrogen-doped carbon quantum dot (NCQD) solution derived from N-methyl-2-pyrrolidone into cobalt-based ZIF-67 to modify the porosity and dope heteroatoms of CoS2 nanoparticle-embedded heteroatom-doped carbon composites (CoS2/NSC). The mildly acidic NCQD solution resulted in the partial etching of the ZIF-67 structure, along with the deposition of NCQDs as a nitrogen source. Notably, the pore sizes could be adjusted by varying the concentration of the NCQD solution, while retaining the nitrogen functional groups during carbonization. The electrode using CoS2/NSC with the 2.8 mL NCQD pre-treatment exhibited enhanced C-rate capability with the capacity of 392 mAh/g at 2.0 A/g. Moreover, the cycling stability was improved, with a capacity retention of 77 % after 100 cycles.

Comprehensive Study of Ti and Ta Co-Doping in Ni-Rich Cathode Material LiNi0.8Mn0.1Co0.1O2 Towards Improving the Electrochemical Performance.

Layered Ni-rich oxides (LiNi1-x-yCoxMnyO2) cathode materials are of current interest in high-energy-demanding applications, such as electric vehicles because of high discharge capacity and high intercalation potential. Here, the effect of co-doping a small amount of Ti and Ta on the crystal structure, morphology, and electrochemical properties of high Ni-rich cathode material LiNi0.8Mn0.1Co0.1-x-yTixTayO2 (0.0≤x+y≤0.2) was systematically investigated. This work demonstrates that an optimum level of Ti and Ta doping is beneficial towards enhancing electrochemical performance. The optimal Ti4+ and Ta5+ co-doped cathode LiNi0.8Mn0.1Co0.09Ti0.005Ta0.005O2 exhibits a superior initial discharge capacity of 161.1 mAh g-1 at 1 C, and excellent capacity retention of 87.1 % after 250 cycles, compared to the pristine sample that exhibits only 59.8 % capacity retention. Moreover, the lithium-ion diffusion coefficients for the co-doped cathode after the 3rd and 50th cycles are 9.9×10-10 cm2 s-1 and 9.3×10-10 cm2 s-1 respectively, which is higher than that of the pristine cathode (3.3×10-10 cm2 s-1 and 2.5×10-10 cm2 s-1 respectively). Based on these studies, we conclude that Ti and Ta co-doping enhances structural stability by mitigating irreversible phase transformation, improving Li-ion kinetics by expanding interlayer spacing, and nanosizing primary particles, thereby stabilizing high-nickel cathode materials and significantly enhancing cyclability.

Colossal Reversible Barocaloric Effects in a Plastic Crystal Mediated by Lattice Vibrations and Ion Diffusion.

Solid-state methods for cooling and heating promise a sustainable alternative to current compression cycles of greenhouse gases and inefficient fuel-burning heaters. Barocaloric effects (BCE) driven by hydrostatic pressure (p) are especially encouraging in terms of large adiabatic temperature changes (|ΔT| ≈ 10K) and isothermal entropy changes (|ΔS| ≈ 100JK-1kg-1). However, BCE typically require large pressure shifts due to irreversibility issues, and sizeable |ΔT| and |ΔS| seldom are realized in a same material. Here, the existence of colossal and reversible BCE in LiCB11H12 is demonstrated near its order-disorder phase transition at ≈380K. Specifically, for Δp ≈ 0.23(0.10)GPa, |ΔSrev| = 280(200)JK-1kg-1 and |ΔTrev| = 32(10)K are measured, which individually rival with state-of-the-art BCE figures. Furthermore, pressure shifts of the order of 0.1GPa yield huge reversible barocaloric strengths of ≈2JK-1kg-1MPa-1. Molecular dynamics simulations are performed to quantify the role of lattice vibrations, molecular reorientations, and ion diffusion on the disclosed BCE. Interestingly, lattice vibrations are found to contribute the most to |ΔS| while the diffusion of lithium ions, despite adding up only slightly to the entropy change, is crucial in enabling the molecular order-disorder phase transition.

Gradient fluorination engineering through interdiffusion reaction for high-voltage LiCoO2

The advancement of high charging cut-off voltage stands as a crucial avenue to enhance the energy density of LiCoO2 (LCO). However, LCO faces severe interface and bulk phase issues at high voltage (≥ 4.6 V), resulting in poor cycling stability. In this study, we reconstruct the surface structure of LCO based on the interdiffusion reaction between LCO and MgF2 in a high-temperature sintering process. Specifically, this interdiffusion reaction yields an ultra-thin LiF coating layer, artificially reinforcing the chemical structure of the cathode-electrolyte interphase (CEI) during cycling. This LiF-rich CEI not only effectively protects the surface structure of LCO, but also facilitates the lithium-ion diffusion. Furthermore, the diffusion of F and Mg into the LCO lattice significantly strengthens the structure, which inhibits unfavorable phase transitions from the O3 phase to the H1–3 phase at high voltage. Consequently, such modified LCO with concurrently enhanced interface and bulk structure exhibits outstanding long-term cycling performance within 3.0–4.6 V at 1 C, achieving a capacity retention of 84.9 % after 1000 cycles. Meanwhile, it also demonstrates excellent high-temperature performance, with a capacity retention of 85.0 % after 200 cycles under 45 °C.

Improved Cycling Stability of LFP by W-Ti Co-Doping Strategy for Li-Ion Batteries

Olivine-type lithium iron phosphate (LFP) is used widely as a cathode material with excellent cycling stability, thermal stability, and low cost for lithium-ion batteries in power vehicles and energy storage. However, it has inherent drawbacks that limit its further development, such as low electronic conductivity and lithium ion diffusion rate. Here, secondary spherical particles LFP-W/Ti@C were synthesized using a simple sanding and spray drying method. The pyrolysis of glucose forms a uniform and dense amorphous carbon on the surface of LFP, and the constructed three-dimensional conductive network accelerates the transfer of electrons and ions while mitigating the volume expansion during the lithiation-delithiation process. In addition, the synergistic co-doping of W/Ti achieves nanosizing of primary particles with more active sites providing locations for lithium ions storage, while reducing polarization and internal resistance and enhancing the diffusion kinetics of lithium ion. The LFP-W/Ti@C obtained after optimization still has a discharge capacity of 107.7 mAh g−1 (with a cycle retention rate of up to 100%) after 500 cycles at 5 C. This simple W/Ti co-doping strategy provides excellent rate performance and shows great potential for fast charging in electric vehicles.

Fluorine-ion-regulated yolk–shell carbon-silicon anode material for high performance lithium ion batteries

Silicon is considered as the next-generation anode material for lithium-ion batteries due to its high theoretical specific capacity and abundant crustal abundance. However, its poor electrical conductivity results in slow diffusion of lithium ions during battery operation. Simultaneously, the alloying process of silicon undergoes a 300 % volume change, leading to structural fractures in silicon during the cycling process.As a result, it loses contact with the current collector, continuously exposing active sites, and forming a sustained solid electrolyte interface (SEI) membrane. This paper presents the design of a fluorine-ion-regulated yolk–shell carbon-silicon anode material, highlighting the following advantages: (a) Alleviating volume changes through the design of a yolk–shell structure, thereby maintaining material structural integrity during cycling. (b) Carbon shell prevents silicon from coming into contact with the electrolyte, simultaneously improving silicon's electrical conductivity and increasing ion/electron conductivity. (c) Utilizing fluorine-ion interface modification to obtain an SEI membrane rich in fluorine components (such as LiF), thereby enhancing its long cycling performance. The F-Si@Void@C exhibits outstanding electrochemical performance, with a reversible capacity of 1166 mAh/g after 900 cycles at a current density of 0.5 A/g.

Mitigating Gas Evolution in Electron Beam-Induced Gel Polymer Electrolytes Through Bi-Functional Cross-Linkable Additives.

The current high-capacity lithium-ion batteries (LIBs), reliant on flammable liquid electrolytes (LEs) and nickel-rich cathodes, are plagued by safety hazards, especially the risk of hazardous gas release stemming from internal side reactions. To address these safety concerns, an electron beam (E-beam)-induced gel polymer electrolyte (E-Gel) is introduced, employing dipentaerythritol hexaacrylate (DPH) as a bi-functional cross-linkable additive (CIA). The dual roles of DPH are exploited through a strategically designed E-beam irradiation process. Applying E-beam irradiation on the pre-cycled cells allows DPH to function as an additive during the initial cycle, establishing a protective layer on the surface of the anode and cathode and as a cross-linker during the E-beam irradiation step, forming a polymer framework. The prepared E-Gel with CIA has superior interfacial compatibility, facilitating lithium-ion diffusion at the electrode/E-Gel interface. The electrochemical assessment of 1.2 Ah pouch cells demonstrates that E-Gel substantially reduces gas release by 2.5 times compared to commercial LEs during the initial formation stage and ensures superior reversible capacity retention even after prolonged cycling at 55°C. The research underscores the synergy of bifunctional CIA with E-beam technology, paving the way for large-scale production of safe, high-capacity, and commercially viable LIBs.

Exploring Layered Disorder in Lithium-Ion-Conducting Li3Y1-xInxCl6.

Li3Y1-xInxCl6 undergoes a phase transition from trigonal to monoclinic via an intermediate orthorhombic phase. Although the trigonal yttrium containing the end member phase, Li3YCl6, synthesized by a mechanochemical route, is known to exhibit stacking fault disorder, not much is known about the monoclinic phases of the serial composition Li3Y1-xInxCl6. This work aims to shed light on the influence of the indium substitution on the phase evolution, along with the evolution of stacking fault disorder using X-ray and neutron powder diffraction together with solid-state nuclear magnetic resonance spectroscopy, studying the lithium-ion diffusion. Although Li3Y1-xInxCl6 with x ≤ 0.1 exhibits an ordered trigonal structure like Li3YCl6, a large degree of stacking fault disorder is observed in the monoclinic phases for the x ≥ 0.3 compositions. The stacking fault disorder materializes as a crystallographic intergrowth of faultless domains with staggered layers stacked in a uniform layer stacking, along with faulted domains with randomized staggered layer stacking. This work shows how structurally complex even the "simple" series of solid solutions can be in this class of halide-based lithium-ion conductors, as apparent from difficulties in finding a consistent structural descriptor for the ionic transport.

Effect of Fe and Zn co-doping on LiCoPO4 cathode materials for High-Voltage Lithium-Ion batteries

Lithium cobalt phosphate (LiCoPO4) has great potential to be developed as a cathode material for lithium-ion batteries (LIBs) due to its structural stability and higher voltage platform with a high theoretical energy density. However, the relatively low diffusion of lithium ions still needs to be improved. In this work, Fe and Zn co-doped LiCoPO4: LiCo0.9-xFe0.1ZnxPO4/C is utilized to enhance the battery performance of LiCoPO4. The electrochemical properties of LiCo0.85Fe0.1Zn0.05PO4/C demonstrated an initial capacity of 118 mAh/g, with 93.4 % capacity retention at 1C after 100 cycles, and a good capacity of 87 mAh/g remained under a high current density of 10C. In addition, the diffusion rate of Li ions was investigated, proving the improvement of the materials with doping. The impedance results also showed a smaller resistance of the doped materials. Furthermore, operando X-ray diffraction displayed a good reversibility of the structural transformation, corresponding to cycling stability. This work provided studies of both the electrochemical properties and structural transformation of Fe and Zn co-doped LiCoPO4, which showed that 10 % Fe and 5 % Zn co-doping enhanced the electrochemical performance of LiCoPO4 as a cathode material in LIBs.