High-performance Lithium-ion Batteries Research Articles

Thermodynamic and Kinetic Behaviors of Electrolytes Mediated by Intermolecular Interactions Enabling High-Performance Lithium-Ion Batteries.

Electrolyte solvation chemistry regulated by lithium salts, solvents, and additives has garnered significant attention since it is the most effective strategy for designing high-performance electrolytes in lithium-ion batteries (LIBs). However, achieving a delicate balance is a persistent challenge, given that excessively strong or weak Li+-solvent coordination markedly undermines electrolyte properties, including thermodynamic redox stability and Li+-desolvation kinetics, limiting the practical applications. Herein, we elucidate the crucial influence of solvent-solvent interactions in modulating the Li+-solvation structure to enhance electrolyte thermodynamic and kinetic properties. As a paradigm, by combining strongly coordinated propylene carbonate (PC) with weakly coordinated cyclopentylmethyl ether (CPME), we identified intermolecular interactions between PC and CPME using 1H-1H correlation spectroscopy. Experimental and computational findings underscore the crucial role of solvent-solvent interactions in regulating Li+-solvent/anion interactions, which can enhance both the thermodynamic (i.e., antireduction capability) and kinetic (i.e., Li+-desolvation process) aspects of electrolytes. Additionally, we introduced an interfacial model to reveal the intricate relationship between solvent-solvent interactions, electrolyte properties, and electrode interfacial behaviors at a molecular scale. This study provides valuable insights into the critical impact of solvent-solvent interactions on electrolyte properties, which are pivotal for guiding future efforts in functionalized electrolyte engineering for metal-ion batteries.

Electrospinning synthesis of hollow V0.95Mo0.97O5 nanofibers for high-performance lithium-ion batteries

We report the facile electrospinning fabrication of hollow V0.95Mo0.97O5 nanofibers via controlling oxidization of the V/Mo/polymer precursor, whose structural evolution upon increasing the annealing temperature are revealed. When examined as anode of lithium-ion batteries, the hollow V0.95Mo0.97O5 nanofibers display superior electrochemical properties with high cycle and rate capability, delivering high reversible capacities of 746.7/583.8 mAh/g at 500/1000 mA/g after 300 cycles, and a high-rate capacity of 614 mAh/g at 2000 mA/g.

Batch-Scale Synthesis and Interfacially Enhanced Stability of Silicon Suboxide-Based Anodes toward High-Performance Lithium-Ion Batteries.

SiOx anode materials are among the most promising candidates for next-generation high-energy-density lithium-ion batteries (LIBs). However, their commercial application is hindered by poor conductivity, low initial Coulombic efficiency (ICE), and an unstable solid electrolyte interface. Developing cost-effective SiOx anodes with high electrochemical performance is crucial for advanced LIBs. To tackle these issues, this study utilized APTES as a silicon source and carbon nanotubes (CNTs) as additives to prepare a T-SiOx/C/CNTs composite material with N doping and in situ carbon coating using a "molecular assembly combined with controlled pyrolysis" strategy under mild conditions. The in situ carbon coating, formed by the pyrolysis of organic groups on the molecular precursor, effectively protects the inner SiOx active material. The introduced CNTs enhance electron migration and improve the rigidity of the carbon coating layer. The prelithiated T-SiOx@C/CNTs electrode achieves an ICE of 91.6%, with a specific capacity of 622 mAh g-1 after 400 cycles at 1 A g-1 and 475.8 mAh g-1 after 800 cycles. Full cell tests with commercial NCM811 cathodes further demonstrate the potential of T-SiOx@C/CNTs as a highly promising anode material. This work provides some insights into the rational design of advanced anode materials for LIBs, paving the way for their future development and application.

Controllable preparation of carbon coating Ge nanospheres with a cubic hollow structure for high-performance lithium ion batteries

Germanium based nanomaterials are very promising as the anodes for the lithium ion batteries since their large specific capacity, excellent lithium diffusivity and high conductivity. However, their controllable preparation is still very difficult to achieve. Herein, we facilely prepare a unique carbon coating Ge nanospheres with a cubic hollow structure (Ge@C) via a hydrothermal synthesis and subsequent pyrolysis using low-cost GeO2 as precursors. The hollow Ge@C nanostructure not only provides abundant interior space to alleviate the huge volumetric expansion of Ge upon lithiation, but also facilitates the transmission of lithium ions and electrons. Moreover, experiment analyses and density functional theory (DFT) calculations unveil the excellent lithium adsorption ability, high exchange current density, low activation energy for lithium diffusion of the hollow Ge@C electrode, thus exhibiting significant lithium storage advantages with a large charge capacity (1483 mAh/g under 200 mA g−1), distinguished rate ability (710 mAh/g under 8000 mA g−1) as well as long-term cycling stability (1130 mAh/g after 900 cycles under 1000 mA g−1). Therefore, this work offers new paths for controllable synthesis and fabrication of high-performance Ge based lithium storage nanomaterials.

Intelligent dual-anode strategy for high-performance lithium-ion batteries

Intelligent dual-anode strategy for high-performance lithium-ion batteries

One-step fabrication of binder-free nanoSi-CNT-carbon black/cyclized PAN composite anode for high-performance lithium-ion batteries

Silicon is one of the most promising anode materials for lithium-ion batteries (LIBs) due to its high theoretical capacity. However, its non-conductive nature and significant volume expansion during lithiation pose challenges. In this study, we developed a novel electrode comprising silicon nanoparticles (nanoSi), carbon nanotubes (CNTs), and carbon black (CB) in cyclized polyacrylonitrile (cPAN), referred to as nanoSi-CNT-CB/cPAN. This electrode is fabricated through a one-step thermal process by heating a cast nanoSi-CNT-CB/PAN film on Cu foil at 310 °C. The LIB performance using the nanoSi-CNT-CB/cPAN electrode shows an impressive initial coulombic efficiency of 93.1 % at 0.1 A g−1, a high specific capacity of 2267.2 mAh g−1 at 0.5 A g−1, and a retention of 89.2 % over 390 cycles, achieving 783 mAh g−1 at 5 A g−1. We attribute these results to the fused cPAN, which provides good adhesion to nanoSi, CNTs, CB, and Cu foil, acting as a binder, active material, and ionic conductive medium. The well-dispersed CNTs and CB form an effective conductive network in the electrode. Additionally, the one-step electrode fabrication is a simple and cost-effective process for next-generation Si-based LIBs.

The study of electrochemical stabilization mechanism of Pt, GC, SS304, Ti and Cu as current collectors for aqueous lithium-ion batteries by electrochemical approaches

This paper employs electrochemical methods (linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS)) to investigate the electrochemical behavior of platinum, glassy carbon, 304 stainless steel, titanium, and copper in 21 and 1 M LiTFSI electrolytes. The LSV results indicate that the electrochemical stability window of the materials varies with the electrolyte concentration, and the stability window is wider in the high-concentration system. Through Tafel polarization curves and EIS analysis, the overpotential of the charge exchange process differs due to the type of material and the concentration of the electrolyte, mainly attributed to the influence of the proportion of free water, electrolyte viscosity, and SEI film formation on electrode process kinetics. After comparative analysis, glassy carbon exhibits a higher overpotential than other materials at both the cathode and anode, effectively suppressing water decomposition. These findings provide theoretical support for the development of high-performance aqueous lithium-ion battery current collector materials.

Optimization of the Operating Voltage of Cobalt-Free Nickel-in-Medium Cathodes for High-Performance Lithium-Ion Batteries

Medium-nickel cobalt-free cathode materials have attracted much attention in recent years for their low cost and high energy density. However, the structural stability of nickel-based cathode materials becomes compromised when accompanied by the increasing of voltage, leading to poor cycling performance and, thus, hindering their widespread industrial application. In this work, we investigated the optimal charge cut-off voltage for the nickel-based cathode material LiNi0.6Mn0.4O2 (NM64). Within the voltage range of 3.0 to 4.5 V, the electrode energy density reached 784.08 Wh/kg, with an initial Coulombic efficiency of 84.49%. The reversible specific capacity at 0.1 C reached 197.84 mAh/g, and it still maintained a high reversible specific capacity of nearly 150 mAh/g, with a capacity retention rate of 86% after 150 cycles at 1 C. Furthermore, NM64 exhibited an intact morphological structure without noticeable cracking after 150 cycles, indicating excellent structural stability. This study emphasizes the relationship between the stability of NM64 cathodes and different operating voltage ranges, thereby promoting the development of high-voltage layered nickel-based cathode materials.

Li1.2Ni0.13Co0.13Mn0.54O2 of Al2O3-coating cathode for high-performance lithium-ion batteries

Li1.2Ni0.13Co0.13Mn0.54O2 of Al2O3-coating cathode for high-performance lithium-ion batteries

Interfacial engineering in SnO2-embedded graphene anode materials for high performance lithium-ion batteries

Tin dioxide is regarded as an alternative anode material rather than graphite due to its high theoretical specific capacity. Modification with carbon is a typical strategy to mitigate the volume expansion effect of SnO2 during the charge process. Strengthening the interface bonding is crucial for improving the electrochemical performance of SnO2/C composites. Here, SnO2-embedded reduced graphene oxide (rGO) composite with a low graphene content of approximately 5 wt.% was in situ synthesized via a cetyltrimethylammonium bromide (CTAB)-assisted hydrothermal method. The structural integrity of the SnO2/rGO composite is significantly improved by optimizing the Sn–O–C electronic structure with CTAB, resulting a reversible capacity of 598 mAh g−1 after 200 cycles at a current density of 1 A g−1. CTAB-assisted synthesis enhances the rate performance and cyclic stability of tin dioxide/graphene composites, and boosts their application as the anode materials for the next-generation lithium-ion batteries.

Controllable Growth of Crystal Facets Enables Superb Cycling Stability of Anode Material for Potassium Ion Batteries

AbstractTo enrich the crystal growth strategies for the booming applications concerning lattice structure, a preferred facet‐growth method is proposed for solvothermal synthesis of target (BiO)2CO3 in the two‐phase system. The dominant crystal phase can be regulated from α‐Fe2O3 to (BiO)2CO3 by properly increasing dosage of Bi feedstock, and the optimized composite is composed of (BiO)2CO3 nanocrystal (≈10 nm) and amorphous iron oxide (defined as “FOB‐50”). Based on experimental characterizations and theoretical calculations, the highly matched lattice between (006)/(0012) facets of α‐Fe2O3 and {010} facet group of (BiO)2CO3 involving orientation of Fe─O─Fe bond and Bi─O─Bi bond is verified to facilitate the interaction between the above facets, resulting in preferred growth of {010} dominated by (040) facet in (BiO)2CO3 and its composites. The structural merits can not only enable the FOB‐50‐based electrodes to achieve a high capacity and unprecedentedly stable cyclic performances for 1500 cycles/a long time‐span of 32 months as anode materials, but also ensure the full‐cell to well inherit the electrochemical features of the cathode in potassium ion batteries (PIBs). This work can provide new insight into lattice regulation for bismuth‐based materials and expand their application as electrodes for high performance PIBs and lithium ion batteries.

Tailoring Alkalized and Oxidized V2CTx as Anode Materials for High-Performance Lithium Ion Batteries.

V2CTx MXenes have gained considerable attention in lithium ion batteries (LIBs) owing to their special two-dimensional (2D) construction with large lithium storage capability. However, engineering high-capacity V2CTx MXenes is still a great challenge due to the limited interlayer space and poor surface terminations. In view of this, alkalized and oxidized V2CTx MXenes (OA-V2C) are envisaged. SEM characterization confirms the accordion-like layered morphology of OA-V2C. The XPS technique illustrates that undergoing alkalized and oxidized treatment, V2CTX MXene replaces -F and -OH with -O groups, which are more conducive to pseudocapacitive properties as well as Na ion diffusion, providing more active sites for ion storage in OA-V2C. Accordingly, the electrochemical performance of OA-V2C as anode materials for LIBs is evaluated in this work, showing excellent performance with high reversible capacity (601 mAh g-1 at 0.2 A g-1 over 500 cycles), competitive rate performance (222.2 mAh g-1 and 152.8 mAh g-1 at 2 A g-1 and 5 A g-1), as well as durable long-term cycling property (252 mAh g-1 at 5 A g-1 undergoing 5000 cycles). It is noted that the intercalation of Na+ ions and oxidation co-modification greatly reduces F surface termination and concurrently increases interlayer spacing in OA-V2C, significantly expediting ion/electron transportation and providing an efficient way to maximize the performance of MXenes in LIBs. This innovative refinement methodology paves the way for building high-performance V2CTx MXenes anode materials in LIBs.

Ultrahigh rate and cycling properties of Li2CuTi3O8 anode derived from HKUST-1 copper source for high-performance lithium-ion batteries

Rational design and preparation of titanium-based anode materials with superior fast charge and discharge are a key focuses of the lithium-ion batteries research. Herein, a novel and facile synthesis of uniformly carbon-coated Li2CuTi3O8 (LCuTO) nanoparticles with excellent high-rate lithium storage properties is presented using HKUST-1 with pore structure and active metal sites as a copper source. The well-designed LCuTO@HKUST with carbon bridges between the particles and the carbon layer on the outer surface offers high electronic conductivity for fast charge and discharge. The LCuTO@HKUST exhibits extraordinary lithium storage performance: high capacity (251.8 mAh/g after 1000 cycles at a current density of 1.0 A/g), a superior high-rate capability (160.3 mAh/g after 500 cycles at 3.0 A/g and 138.1 mAh/g after 500 cycles at 5.0 A/g), and excellent cycle reversibility and cycle stability under various current densities. In addition, the lower Li+ migration barrier in LCuTO@HKUST demonstrated by density functional theory (DFT) calculations is beneficial to the long-cycle stability and high-rate performance. The proposed preparation method and the strategy of using the MOF as a metal source for lithium-ion battery anode materials provide a new approach for advanced fast charge–discharge energy storage applications.

In-situ synthesis of Fe3O4@Fe3C nanoparticles with heterostructures embedded in the N-doped porous carbon for high-performance lithium ion batteries

Metal oxides (Fe3O4) have attracted immense attention as high-capacity anode materials for high-performance electrochemical energy storage systems. However, the large structural change and sluggish reaction kinetics in the lithiation and delithiation reactions critically limit their practical development. Here, we design a novel composite consisting of Fe3O4@Fe3C nanoparticles embedded in N-doped porous carbon (Fe3O4@Fe3C-NPC) for lithium ion batteries. Benefiting from the synergistic effect of heterostructures, the Fe3O4@Fe3C-NPC delivers high reversible capacities (911.9 mAh g−1 at 0.2 A g−1, 319.6 mAh g−1 at 5.0 A g−1). The formed heterointerfaces can build an internal electric field, which help to improve reaction kinetics with fast ion diffusion kinetics and low charge transfer resistance. Furthermore, the Fe3O4@Fe3C-NPC//LiFePO4 full cell also displays great performance. The structural design concept and efficient synthesis method in the work can be extended to construct metal oxide/carbide heterostructures for anode materials.

Microfiber/Nanofiber/Attapulgite Multilayer Separator with a Pore-Size Gradient for High-Performance and Safe Lithium-Ion Batteries.

Lithium-ion batteries (LIBs) have an extremely diverse application nowadays as an environmentally friendly and renewable new energy storage technology. The porous structure of the separator, one essential component of LIBs, provides an ion transport channel for the migration of ions and directly affects the overall performance of the battery. In this work, we fabricated a composite separator (GOP-PH-ATP) via simply laminating an electrospun polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP) nanofibrous membrane coated with attapulgite (ATP) nanoparticles onto a PP nonwoven microfibrous fabric, which exhibits a unique porous structure with a pore-size gradient along the thickness direction that ranges from tens of microns to hundreds of nanometers. As a result, besides the enhanced thermal stability given by the chosen materials, the GOP-PH-ATP separator was endowed with a superhigh porosity of ~95%, strong affinity with electrolyte, and great electrolyte uptake of ~760%, thus effectively enabling an ionic conductivity of 2.38 mS cm-1 and a lithium-ion transference number of 0.62. Furthermore, the cell with the GOP-PH-ATP separator shows an excellent cycling performance with a capacity retention of 91.2% after 150 cycles at 1 C, suggesting that the composite separator with a pore-size gradient structure has great potential to be applied in LIBs.

NiCo Nanoparticles Encapsulated in Nitrogen-Doped Carbon Tubes as Anode Materials for High-Performance Lithium-Ion Batteries

NiCo Nanoparticles Encapsulated in Nitrogen-Doped Carbon Tubes as Anode Materials for High-Performance Lithium-Ion Batteries

CALiSol-23: Experimental electrolyte conductivity data for various Li-salts and solvent combinations

Ion transport in non-aqueous electrolytes is crucial for high performance lithium-ion battery (LIB) development. The design of superior electrolytes requires extensive experimentation across the compositional space. To support data driven accelerated electrolyte discovery efforts, we curated and analyzed a large dataset covering a wide range of experimentally recorded ionic conductivities for various combinations of lithium salts, solvents, concentrations, and temperatures. The dataset is named as ’Conductivity Atlas for Lithium salts and Solvents’ (CALiSol-23). Comprehensive datasets are lacking but are critical to building chemistry agnostic machine learning models for conductivity as well as data driven electrolyte optimization tasks. CALiSol-23 was derived from an exhaustive review of literature concerning experimental non-aqueous electrolyte conductivity measurement. The final dataset consists of 13,825 individual data points from 27 different experimental articles, in total covering 38 solvents, a broad temperature range, and 14 lithium salts. CALiSol-23 can help expedite machine learning model development that can help in understanding the complexities of ion transport and streamlining the optimization of non-aqueous electrolyte mixtures.

Metal alkoxides: A new type of reversible anode materials for stable and high-rate lithium-ion batteries

Metal-organic compounds have attracted significant attention for lithium-ion battery (LIB) anodes. However, their practical application is severely hindered by the poor structural stability and sluggish Li+ reaction kinetics. Herein, we proposed a new type of metal–organic compound, metal alkoxides, for high-performance LIBs. A series of metal-alkoxide/graphene composites with different transition metal centers and alkoxide anions are prepared to investigate the structural stability, Li-storage ability, and Li+ diffusion kinetics. The results reveal that the metal centers and alkoxide anions have significant influence on the structural stability, molar mass, and electronic structures, which are highly related to the Li-storage performance. Among them, Co-EG/rGO (EG represents the ethylene glycol anion) delivers the best performance involving high specific capacity (975 mAh g−1 at 0.2 A g−1), excellent rate capability (400.8 mAh g−1 at 10 A g−1), and stable cycling performance (86.8 % capacity retention after 600 cycles) due to its stable structure, smaller molar mass, and favorable electronic structure. Moreover, the Li-storage mechanism and solid electrolyte interphase (SEI) evolution of the Co-EG/rGO electrode are studied in detail through multiple ex-situ/in-situ characterizations. This work provides a new type of metal alkoxide anode material for high-rate and long-life LIBs toward practical energy applications.

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

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

Co-Assembly of Polyoxometalates and Porphyrins as Anode for High-Performance Lithium-Ion Batteries.

Polyoxometalates (POMs) have been considered one of the most promising anode candidates for lithium-ion batteries (LIBs) in virtue of their high theoretical capacity and reversible multielectron redox properties. However, the poor intrinsic electronic conductivity, low specific surface area, and high solubility in organic electrolytes hinder their widespread applications in LIBs. Herein, a novel hybrid nanomaterial is synthesized by co-assembling POMs and porphyrins (PMo12/CoTPyP) through a facile solvothermal method. The POM clusters are stabilized by porphyrin units through electrostatic interactions, which simultaneously realize the uniform dispersion of POMs and porphyrin units. Benefiting from the generated sub-1nm channels for fast ion transport and the synergistic effect between evenly distributed PMo12 clusters and high-conductive CoTPyP units, the LIB based on the optimized PMo12/CoTPyP anode exhibits significantly improved Li+ storage capability as well as superior rate and cycling performance. The results of density functional theory simulations further reveal that the co-assembly of PMo12 and CoTPyP can accelerate the mobility of Li+ and electrons, which in turn promotes the enhancement of LIBs performance. This work paves a strategy for synthesizing POMs-based anode materials with simultaneously high dispersibility, redox activity, and stability.