Dynamic phase evolution of MoS3 accompanied by organodiselenide mediation enables enhanced performance rechargeable lithium battery.

Considerable efforts have been devoted to Li-S batteries, typically the soluble polysulfides shuttling effect. As a typical transition metal sulfide, MoS2 is a magic bullet for addressing the issues of Li-S batteries, drawing increasing attention. In this study, we introduce amorphous MoS3 as analogous sulfur cathode material and elucidate the dynamic phase evolution in the electrochemical reaction. The metallic 1T phase incorporated 2H phase MoS2 with sulfur vacancies (SVs-1T/2H-MoS2) decomposed from amorphous MoS3 achieves refined mixing with the "newborn" sulfur at the molecular level and supplies continuous conduction pathways and controllable physical confinement. Meanwhile, the in situ-generated SVs-1T/2H-MoS2 allows lithium intercalation in advance at high discharge voltage (≥1.8 V) and enables fast electron transfer. Moreover, aiming at the unbonded sulfur, diphenyl diselenide (PDSe), as a model redox mediator is applied, which can covalently bond sulfur atoms to form conversion-type organoselenosulfides, changing the original redox pathway of "newborn" sulfur in MoS3, and suppressing the polysulfides shuttling effect. It also significantly lowers the activation energy and thus accelerates the sulfur reduction kinetics. Thus, the in situ-formed intercalation-conversion hybrid electrode of SVs-1T/2H-MoS2 and organoselenosulfides realizes enhanced rate capability and superior cycling stability. This work provides a novel concept for designing high-energy-density electrode materials.

A Non-Flammable and Flexible Aluminum Derived Lithium-Ion Storage Device with a Wide Temperature Range of Operation.

With the rapid development and increasing popularity of electric vehicles and wearables, battery safety has become a leading focus in the field of energy storage research. Specifically, aluminum-ion batteries are gaining increasing attention as low-cost energy-storage systems with high safety levels and theoretical energy density. However, the dense alumina passivation layer on the aluminum anode surface and slow kinetic performance of commonly used ionic liquid electrolytes still render poor performance. This report presents a new type of aluminum-derived lithium-ion battery (ALIB) that maintains a certain discharge performance under damaging conditions, including continuous bending, high- and low-temperature environments, and shearing. This new ALIB effectively meets the current demand for flexible and wearable batteries. The prepared ALIB achieves a stable cycle of 130 mAh g-1 specific capacity and ≈260 Wh kg-1 theoretical energy density at a wide voltage platform of 2 V and a test temperature of 25 °C without undergoing combustion. Additionally, the study analyzes the reaction mechanism of this ALIB based on density functional theory and conducts ex situ XRD and XPS analyses to elucidate the underlying storage mechanism.

Nano-Interfacial Supramolecular Adhesion of Metal-Organic Framework-Based Separator Enables High-Safety and Wide-Temperature-Range Lithium Batteries.

Polyolefin separators are the most commonly used separators for lithium batteries; however, they tend to shrink when heated, and their Li+ transference number (t Li +) is low. Metal-organic frameworks (MOFs) are expected to solve the above problems due to their high thermal stability, abundant pore structure, and open metal sites. However, it is difficult to prepare high-porosity MOF-based membranes by conventional membrane preparation methods. In this study, a high-porosity free-standing MOF-based safety separator, denoted the BCM separator, is prepared through a nano-interfacial supramolecular adhesion strategy. The BCM separator has a large specific surface area (450.22 m2 g-1) and porosity (62.0%), a high electrolyte uptake (475 wt%), and can maintain its morphology at 200 °C. The ionic conductivity and t Li + of the BCM separator are 1.97 and 0.72 mS cm-1, respectively. Li//LiFePO4 cells with BCM separators have a capacity retention rate of 95.07% after 1100 cycles at 5  C, a stable high-temperature cycling performance of 300 cycles at 80 °C, and good capacity retention at -40 °C. Li//NCM811 cells with BCM separators exhibit significantly improved rate performance and cycling performance. Pouch cells with BCM separators can work at 120 °C and have good safety at high temperature.

Dendrite-Free Dual-Phase Li-Ba Alloy Anode Enabled by Ordered Array of Built-in Mixed Conducting Microchannels.

The development and application of lithium (Li) anode is hindered by volumetric variation, dendritic Li growth, and parasitic reactions. Herein, a dual-phase Li-barium (Ba) alloy with self-assembled microchannels array is synthesized through a one-step thermal fusion method to investigate the inhibition effect of lithiophilic composite porous array on Li dendrites. The Li-rich Li-Ba alloy (BaLi24) as composite Li electrode exhibits an ordered porous structure of BaLi4 intermetallic compound after delithiation, which acts as a built-in 3D current collector during Li plating/striping process. Furthermore, the lithiophilic BaLi4 alloy scaffold is a mixed conductor, featuring with Li+ ions diffusion capability, which can efficiently transport the reduced Li to the interior of the electrode structure. This unique top-down growth mode can effectively prohibit Li dendrites growth and improve the space utilization of 3D electrode structure. The spin-polarized density functional theory (DFT) calculations suggest that the absorption capability of BaLi4 benefits the deposition of Li metal. As a result, the cell performance with the dual-phase Li-Ba alloy anode is significantly improved.

Vertically-Aligned Card-House Structure for Composite Solid Polymer Electrolyte with Fast and Stable Ion Transport Channels.

All-solid-state lithium batteries (ASSLBs) are highly promising as next-generation energy storage devices owing to their potential for great safety and high energy density. This work demonstrates that composite solid polymer electrolyte with vertically-aligned card-house structure can simultaneously improve the high rate and long-term cycling performance of ASSLBs. The vertical alignment of laponite nanosheets creates fast and uniform Li+ ion transport channels at the nanosheets/polymer interphase, resulting in high ionic conductivity of 8.9 × 10-4 S cm-1 and Li+ transference number of 0.32 at 60 °C, as well as uniformly distributed solid electrolyte interphase. Such electrolyte is characterized by high mechanical strength, low flammability, excellent structural stability and stable ion transport channels. In addition, the ASSLB cell with the electrolyte and LiFePO4 cathode delivers a high discharge specific capacity of 124.8 mAh g-1, which accounts for 85.6% of its initial capacity after 500 cycles at 1C. The reasonable design through structural control strategy by interconnecting the vertically-aligned nanosheets open a way to fabricate high performance composite solid polymer electrolytes.

Enhanced Low-Temperature Resistance of Lithium-Metal Rechargeable Batteries Based on Electrolyte Including Ethyl Acetate and LiDFOB Additives.

To meet the demand for higher energy density in lithium-ion batteries and expand their application range, coupling lithium metal anodes with high-voltage cathodes is an ideal solution. However, the compatibility between lithium metal batteries and electrolytes affects their applicability. In this study, proposes a locally concentrated electrolyte based on ethyl acetate (EA) as the solvent, lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) as the lithium salt, and lithium difluorooxoborate (LiDFOB) as a sacrificial agent to enhance the low-temperature and high-voltage endurance of Li//Lithium cobalt oxide (LCO) batteries. The Li//LCO battery can operate within the voltage range of 3 to 4.5 V, with an initial discharge specific capacity of 174.5 mAh g-1 at 20 °C. At -40 °C, after 200 cycles, the capacity retention rate is 87.7 %. It can operate under extreme conditions of -70 °C, with a discharge specific capacity of 112.6 mAh g-1. Additionally, LCO//HC batteries using this electrolyte demonstrate excellent performance. Present work provides a new perspective for the optimization of electrolytes for low-temperature lithium-ion batteries.

Concentration controlling of carboxylic ester-based electrolyte for low temperature lithium-ion batteries.

Low temperature has been a major challenge for lithium-ion batteries (LIBs) to maintain satisfied electrochemical performance, and the main reason is the deactivation of electrolyte with the decreasing temperature. To address this point, in present work, we develop a low-temperature resistant electrolyte which includes ethyl acetate (EA) and fluoroethylene carbonate (FEC) as solvent and lithium difluoro(oxalato)borate (LiDFOB) as the primary lithium salt. Due to the preferential decomposition of LiDFOB and FEC, a solid electrolyte interface rich in LiF is formed on the lithium metal anodes (LMAs) and lithium cobalt oxide (LCO) cathodes, contributing to higher stability and rapid desolvation of Li+ ions. The batteries with the optimized electrolyte can undergo cycling tests at -40 °C, with a capacity retention of 83.9 % after 200 cycles. Furthermore, the optimized electrolyte exhibits excellent compatibility with both LCO cathodes and graphite (Gr) anodes, enabling a Gr/LCO battery to maintain a capacity retention of 90.3 % after multiple cycles at -25 °C. This work proposes a cost-effective electrolyte that can activate potential LIBs in practical scenarios, especially in low-temperature environments.

Enhancing mechanical properties of composite solid electrolyte by ultra-high molecular weight polymers.

Composite solid electrolytes combining the advantages of inorganic and polymer electrolytes are considered as one of the promising candidates for solid-state lithium metal batteries. Compared with ceramic-in-polymer electrolyte, polymer-in-ceramic electrolyte displays excellent mechanical strength to inhibit lithium dendrite. However, polymer-in-ceramic electrolyte faces the challenges of lack of flexibility and severely blocked Li+transport. In this study, we prepared polymer-in-ceramic film utilizing ultra-high molecular weight polymers and ceramic particles to combine flexibility and mechanical strength. Meanwhile, the ionic conductivity of polymer-in-ceramic electrolytes was improved by adding excess lithium salt in polymer matrix to form polymer-in-salt structure. The obtained film shows high stiffness (10.5 MPa), acceptable ionic conductivity (0.18 mS cm-1) and high flexibility. As a result, the corresponding lithium symmetric cell stably cycles over 800 h and the corresponding LiFePO4cell provides a discharge capacity of 147.7 mAh g-1at 0.1 C without obvious capacity decay after 145 cycles.

Enzymatic Upcycling of PET Waste to Calcium Terephthalate for Battery Anodes.

Biotechnological recycling offers a promising solution to address the environmental concerns associated with waste plastics, particularly polyethylene terephthalate (PET), widely utilized in packaging materials and textiles. To advance the development of a bio-based circular plastic economy, innovative upcycling strategies capable of generating higher-value products are needed. In this study, we enhanced the enzymatic depolymerization of waste PET by incorporating highly concentrated calcium ions (up to 1 m) to the hydrolytic reaction catalyzed by the best currently known enzyme LCCICCG . The presence of calcium ions not only improved the thermal stability and activity of the biocatalyst but also significantly reduced the consumption of base required to maintain optimal pH levels. Employing optimized conditions at 80 °C for 12 h, we successfully converted ≈84 % of the waste PET (200 g L-1 ) into solid hydrated calcium terephthalate (CaTP ⋅ 3H2 O) as the primary product instead of soluble terephthalate salt. CaTP ⋅ 3H2 O was easily purified and employed as a raw material for battery electrode production, exhibiting an initial reversible specific capacity of 164.2 mAh g-1 . Through techno-economic analysis, we conclusively demonstrated that the one-pot biocatalysis-based synthesis of CaTP is a superior PET upcycling strategy than the secondary synthesis method employing recycled terephthalic acid.

Build a High-Performance All-Solid-State Lithium Battery through Introducing Competitive Coordination Induction Effect in Polymer-Based Electrolyte.

Polymer-inorganic composite electrolytes (PICE) have attracted tremendous attention in all-solid-state lithium batteries (ASSLBs) due to facile processability. However, the poor Li+ conductivity at room temperature (RT) and interfacial instability severely hamper the practical application. Herein, we propose a concept of competitive coordination induction effects (CCIE) and reveal the essential correlation between the local coordination structure and the interfacial chemistry in PEO-based PICE. CCIE introduction greatly enhances the ionic conductivity and electrochemical performances of ASSLBs at 30 °C. Owing to the competitive coordination (Cs+…TFSI-…Li+, Cs+…C-O-C…Li+ and 2,4,6-TFA…Li…TFSI-) from the competitive cation (Cs+ from CsPF6) and molecule (2,4,6-TFA: 2,4,6-trifluoroaniline), a multimodal weak coordination environment of Li+ is constructed enabling a high efficient Li+ migration at 30 °C (Li+ conductivity: 6.25×10-4 S cm-1; tLi +=0.61). Since Cs+ tends to be enriched at the interface, TFSI- and PF6 - in situ form LiF-Li3N-Li2O-Li2S enriched solid electrolyte interface with electrostatic shielding effects. The assembled ASSLBs without adding interfacial wetting agent exhibit outstanding rate capability (LiFePO4: 147.44 mAh g-1@1 C and 107.41mAhg-1@2 C) and cycling stability at 30 °C (LiFePO4:94.65 %@200cycles@0.5 C; LiNi0.5Co0.2Mn0.3O2: 94.31 %@200 cycles@0.3 C). This work proposes a concept of CCIE and reveals its mechanism in designing PICE with high ionic conductivity as well as high interfacial compatibility at near RT for high-performance ASSLBs.

A Dynamically Stable Sulfide Electrolyte Architecture for High-Performance All-Solid-State Lithium Metal Batteries.

All-solid-state batteries employing sulfide solid electrolyte and Li metal anode are promising because of their high safety and energy densities. However, the interface between Li metal and sulfides suffers from catastrophic instability which stems the practical use. Here, a dynamically stable sulfide electrolyte architecture to construct the hierarchy of interface stability is reported. By rationally designing the multilayer structures of sulfide electrolytes, the dynamic decomposing-alloying process from MS4 (M = Ge or Sn) unit in sulfide interlayer can significantly prohibit Li dendrite penetration is revealed. The abundance of highly electronic insulating decompositions, such as Li2 S, at the sulfide interlayer interface helps to well constrain the dynamic decomposition process and preserve the long-term polarization stability is also highlighted. By using Li6 PS5 Cl||Li10 SnP2 S12 ||Li6 PS5 Cl electrolyte architecture, Li metal anode shows an unprecedented critical current density over 3 mA cm-2 and achieves the steady over-potential for ≈900 hours. Based upon the merits, the Li||LiNi0.8 Co0.1 Mn0.1 O2 battery delivers a remarkable 75.3% retention even after 600 cycles at 1 C (1C-0.95 mA cm-2 ) under a low stack pressure of 15 MPa.

Advances in Ordered Architecture Design of Composite Solid Electrolytes for Solid-State Lithium Batteries.

Solid electrolyte lithium batteries are the next generation of advanced energy devices. The incorporation of solid electrolytes can significantly improve the safety issue of lithium-ion batteries. Organic-inorganic composite solid electrolytes (CSE) are promising candidates for solid-state batteries, but their application is mainly limited by low ionic conductivity. Many studies have shown that the architecture of ordered inorganic fillers in CSE can act as fast lithium-ion transfer channels by auxiliary means, thus significantly improving the ionic conductivities. This review summarises the recent advances in CSE with different dimensional inorganic fillers. Various effective strategies for the construction of ordered structures in CSE are then presented. The review concludes with an outlook on the future development of CSE. This review aims to provide researchers with an in-depth understanding of how to achieve ordered architectures in CSE for advanced solid state lithium batteries.

Glass Fiber Reinforced Epoxy-Amine Thermosets and Solvate IL: Towards New Composite Polymer Electrolytes for Lithium Battery Applications.

To effectively use (Li) lithium metal anodes, it is becoming increasingly necessary to create membranes with high lithium conductivity, electrochemical and thermal stabilities, as well as adequate mechanical properties. Composite gel polymer electrolytes (CGPE) have emerged as a promising strategy, offering improved ionic conductivity and structural performance compared to polymer electrolytes. In this study, a simple and scalable approach was developed to fabricate a crosslinked polyethylene oxide (PEO)-based membrane, comprising two different glass fiber reinforcements, in terms of morphology and thickness. The incorporation of a solvated ionic liquid into the developed membrane enhances the ionic conductivity and reduces flammability in the resulting CGPE. Galvanostatic cycling experiments demonstrate favorable performance of the composite membrane in symmetric Li cells. Furthermore, the CGPE demonstrated electrochemical stability, enabling the cell to cycle continuously for more than 700 h at a temperature of 40 °C without short circuits. When applied in a half-cell configuration with lithium iron phosphate (LFP) cathodes, the composite membrane enabled cycling at different current densities, achieving a discharge capacity of 144 mAh·g-1. Overall, the findings obtained in this work highlight the potential of crosslinked PEO-based composite membranes for high-performance Li metal anodes, with enhanced near room temperature conductivity, electrochemical stability, and cycling capability.

In Situ Low-Temperature Carbonization Capping of LiFePO4 with Coke for Enhanced Lithium Battery Performance.

Lithium batteries incorporating LiFePO4 (LFP) as the cathode material have gained significant attention in recent research. However, the limited electronic and ionic conductivity of LFP poses challenges to its cycling performance and overall efficiency. In this study, we address these issues by synthesizing a series of LiFePO4/carbon (LFP/C) composites through low-temperature carbonization coating of LFP in the presence of Coke as the carbon source. The resulting lithium batteries utilizing LFP/C as the cathode material exhibited impressive discharge specific capacities of 148.35 mA·h/g and 126.74 mA·h/g at 0.1 C and 1 C rates, respectively. Even after 200 cycles of charging and discharging, the capacities remained remarkably high, with values of 93.74% and 97.05% retention, showcasing excellent cycling stability. Notably, the LFP/C composite displayed exceptional rate capability, and capacity retention of 99.27% after cycling at different multiplication rates. These findings underscore the efficacy of in situ low-temperature carbonization capping of LFP with Coke in significantly improving both the cycling stability and rate capability of lithium batteries.

Multi-Fractal Weibull Adaptive Model for the Remaining Useful Life Prediction of Electric Vehicle Lithium Batteries.

In this paper, an adaptive remaining useful life prediction model is proposed for electric vehicle lithium batteries. Capacity degradation of the electric car lithium batteries is modeled by the multi-fractal Weibull motion. The varying degree of long-range dependence and the 1/f characteristics in the frequency domain are also analyzed. The age and state-dependent degradation model is derived, with the associated adaptive drift and diffusion coefficients. The adaptive mechanism considers the quantitative relations between the drift and diffusion coefficients. The unit-to-unit variability is considered a random variable. To facilitate the application, the convergence of the RUL prediction model is proved. Replacement of the lithium battery in the electric car is recommended according to the remaining useful life prediction results. The effectiveness of the proposed model is shown in the case study.

In Situ Polymerized 1,3-Dioxolane Electrolyte for Integrated Solid-State Lithium Batteries.

Solid-state lithium batteries are promising and safe energy storage devices for mobile electronics and electric vehicles. In this work, we report a facile in situ polymerization of 1,3-dioxolane electrolytes to fabricate integrated solid-state lithium batteries. The in situ polymerization and formation of solid-state dioxolane electrolytes on interconnected carbon nanotubes (CNTs) and active materials is the key to realizing a high-performance battery with excellent interfacial contact among CNTs, active materials and electrolytes. Therefore, the electrodes could be tightly integrated into batteries through the CNTs and electrolyte. Electrons/ions enable full access to active materials in the whole electrode. Electrodes with a low resistance of 4.5â€…Ω â–¡-1 and high lithium-ion diffusion efficiency of 2.5×10-11  cm2 s-1 can significantly improve the electrochemical kinetics. Subsequently, the batteries demonstrated high energy density, amazing charge/discharge rate and long cycle life.

Probing the Origin of Viscosity of Liquid Electrolytes for Lithium Batteries.

Viscosity is an extremely important property for ion transport and wettability of electrolytes. Easy access to viscosity values and a deep understanding of this property remain challenging yet critical to evaluating the electrolyte performance and tailoring electrolyte recipes with targeted properties. We proposed a screened overlapping method to efficiently compute the viscosity of lithium battery electrolytes by molecular dynamics simulations. The origin of electrolyte viscosity was further comprehensively probed. The viscosity of solvents exhibits a positive correlation with the binding energy between molecules, indicating viscosity is directly correlated to intermolecular interactions. Salts in electrolytes enlarge the viscosity significantly with increasing concentrations while diluents serve as the viscosity reducer, which is attributed to the varied binding strength from cation-anion and cation-solvent associations. This work develops an accurate and efficient method for computing the electrolyte viscosity and affords deep insight into viscosity at the molecular level, which exhibits the huge potential to accelerate advanced electrolyte design for next-generation rechargeable batteries.

Understanding LiI-LiBr Catalyst Activity for Solid State Li2S/S Reactions in an All-Solid-State Lithium Battery.

Li||MoS2 solid-state batteries have higher volumetric energy density and power density than Li||Li2S batteries. However, they suffer from energy and power decay due to the formation of lithium sulfide that has low ionic/electronic conductivity and a strong Li-S bond. Herein, we overcome these challenges by incorporating the catalytic LiI-LiBr compound and carbon black into MoS2. The comprehensive simulations, characterizations, and electrochemical evaluations demonstrated that LiI-LiBr significantly reduces Li+/S2- interaction and increases the ionic conductivity of Li2S, thus enhancing the reaction kinetics and Li2S/S redox reversibility. MoS2@LiI-LiBr@C||Li cells with an areal capacity of 0.87 mAh cm-2 provide a reversible capacity of 816.2 mAh g-1 at 200 mA g-1 and maintain 604.8 mAh g-1 (based on the mass of MoS2) for 100 cycles. At a high areal capacity of 2 mAh cm-2, the battery still delivers reversible capacity of 498 mAh g-1. LiI-LiBr-carbon additive can be broadly applied for all transition-metal sulfide cathodes to enhance the cyclic and rate performance.

A Rigid-Flexible Protecting Film with Surface Pits Structure for Dendrite-Free and High-Performance Lithium Metal Anode.

An artificial organic/inorganic composite protecting film for lithium metal anode with one-side surface pits structure was prepared by poly(vinylidene fluoride-co-hexafluoropropylene) and Al2O3+LiNO3 inorganic additives. Due to the unique surface structure, the composite film can not only serve as an artificial protective film, but also act as an additional lithium plating host, which synergistically enabled the lithium metal anode to adapt to high current densities meanwhile maintain dendrite-free during long-term cycling. As a result, the protected lithium metal anode can operate stably for 1000 h at a high current density of 10.0 mA cm-2. When paired with a LiFePO4 or sulfur cathode, the full cells with unflooded electrolyte showed significantly improved cycling performance, demonstrating great potential of this artificial protecting film in lithium metal batteries.

Ionic Rectification across Ionic and Mixed Conductor Interfaces.

In electrochemical devices, it is important to control the ionic transport between the electrodes and solid electrolytes. However, it is difficult to tune the transport without applying an electric field. This paper presents a method to modulate the transport via tuning of the electrochemical potential difference by controlling the electronic states at the interfaces. We fabricated thin-film solid-state Li batteries using LiTi2O4 thin films as positive electrodes. The spontaneous Li-ion transport between the solid electrolyte and LiTi2O4 is controlled by tuning the electrochemical potential difference via use of an electrically conducting Nb-doped SrTiO3 substrate. This study establishes the foundation for rectifying the ionic transport via electronic energy band alignment.