Cross-Linked Solid Polymer Electrolyte for All-Solid-State Rechargeable Lithium Batteries

Collaborative Design of Multi-Molecules Boosts the Performance of the Full-Range Three-Dimensional Quasi-Solid Polymer Electrolyte for Lithium Metal Batteries

Solid polymer electrolytes, known for their ease of processing and excellent interfacial contact, play a crucial role in developing high-energy-density lithium metal batteries. To address the limitations of single-function polymer electrolytes such as polyethylene oxide and polyacrylonitrile, it's imperative to develop polymer electrolytes with superior comprehensive performance by incorporating functional organic molecules. In this study, a quasi-solid polymer electrolyte named VAPE is prepared using a multivariate molecular synergistic strategy. This approach integrates vinyl acetate (VAC), acrylonitrile (AN), and trimethylolpropane ethoxylate triacylate (ETPTA) into a full-range, 3D cross-linked network via radical-initiated polymerization. The cross-linked structure and the synergistic effect of multiple functional units accelerate the lithium-ion transport kinetics of VAPE and induce the formation of dense and stable solid-electrolyte interphase and cathode-electrolyte interphase layers. As a result, the assembled Li/VAPE13/Li symmetric cell exhibits stable cycling for over 800 h. Furthermore, the terpolymer electrolyte VAPE13 demonstrates an electrochemical window up to 5.30 V. Therefore, the LiNi0.8Mn0.1Co0.1O2 (NCM811)/VAPE13/Li battery displays excellent cycling stability with 80% capacity retention after 350 cycles at 0.5C. Even at the ultra-high cut-off voltage of 4.7 V, the NCM811/VAPE13/Li battery achieves a capacity retention rate of 84.8% after 100 cycles at 0.2C.

PDOL-Based Solid Electrolyte Toward Practical Application: Opportunities and Challenges

Polymer solid-state lithium batteries (SSLB) are regarded as a promising energy storage technology to meet growing demand due to their high energy density and safety. Ion conductivity, interface stability and battery assembly process are still the main challenges to hurdle the commercialization of SSLB. As the main component of SSLB, poly(1,3-dioxolane) (PDOL)-based solid polymer electrolytes polymerized in-situ are becoming a promising candidate solid electrolyte, for their high ion conductivity at room temperature, good battery electrochemical performances, and simple assembly process. This review analyzes opportunities and challenges of PDOL electrolytes toward practical application for polymer SSLB. The focuses include exploring the polymerization mechanism of DOL, the performance of PDOL composite electrolytes, and the application of PDOL. Furthermore, we provide a perspective on future research directions that need to be emphasized for commercialization of PDOL-based electrolytes in SSLB. The exploration of these schemes facilitates a comprehensive and profound understanding of PDOL-based polymer electrolyte and provides new research ideas to boost them toward practical application in solid-state batteries.

Chemistry Aspects and Designing Strategies of Flexible Materials for High-Performance Flexible Lithium-Ion Batteries

In recent years, flexible and wearable electronics such as smart cards, smart fabrics, bio-sensors, soft robotics, and internet-linked electronics have impacted our lives. In order to meet the requirements of more flexible and adaptable paradigm shifts, wearable products may need to be seamlessly integrated. A great deal of effort has been made in the last two decades to develop flexible lithium-ion batteries (FLIBs). The selection of suitable flexible materials is important for the development of flexible electrolytes self-supported and supported electrodes. This review is focused on the critical discussion of the factors that evaluate the flexibility of the materials and their potential path toward achieving the FLIBs. Following this analysis, we present how to evaluate the flexibility of the battery materials and FLIBs. We describe the chemistry of carbon-based materials, covalent-organic frameworks (COFs), metal-organic frameworks (MOFs), and MXene-based materials and their flexible cell design that represented excellent electrochemical performances during bending. Furthermore, the application of state-of-the-art solid polymer and solid electrolytes to accelerate the development of FLIBs is introduced. Analyzing the contributions and developments of different countries has also been highlighted in the past decade. In addition, the prospects and potential of flexible materials and their engineering are also discussed, providing the roadmap for further developments in this fast-evolving field of FLIB research.

Feasibility of Multifunctional Cellulose-Based Polysalt as a Polymer Matrix for Li Metal Polymer Batteries

Li metal secondary batteries known for their high energy and power density are the much-awaited energy storage systems owing to the high specific capacity of Li metal. However, due to the instability of Li metal with common Li-ion battery electrolytes, a combination with a polymer electrolyte seems to be an effective strategy to alleviate the safety issues of employing Li metal and provide design conformity to the system. Current trends show improvements in different aspects, such as improving ionic conductivity, single-ion conductivity, mechanical stability, and electrochemical stability. A combination of all these properties has been a bottleneck for the development of polymer electrolytes for safe and efficient operation of all solid-state batteries. Herein, a multifunctional polysalt has been synthesized from green and sustainable materials, namely, ethyl cellulose, plasticized with adiponitrile, that contributes to meeting the critical properties enabling high compatibility with Li metal and a quasi-single-ion-conducting property while simultaneously acting as a matrix/filler for efficient operation of the cells. This multifunctional polymer matrix inhibits further decomposition of nitrile-based plasticizers on Li metal anodes with the formation of a favorable Li metal anode interface, thus enabling the utilization of high-voltage stable nitrile-based plasticizers (4.2 V) to be implemented as an electrolyte component for realization of high-voltage Li metal anode polymer batteries.

Cellulose nanofiber-reinforced solid polymer electrolytes with high ionic conductivity for lithium batteries

Lithium-metal electrodes are promising for developing next-generation lithium-based batteries with high energy densities. However, their implementation is severely limited by dendritic growth during battery cycling, which eventually short-circuits the battery. Replacing conventional liquid electrolytes with solid polymer electrolytes (SPEs) can suppress dendritic growth. Unfortunately, in SPEs the high stiffness required for suppressing dendrites comes at the expense of efficient lithium-ion transport. Some polymer-based composite electrolytes, however, enable the decoupling of stiffness and ionic conductivity. This study introduces a composite SPE comprised of a relatively soft poly(ethylene oxide-co-epichlorohydrin) (EO-co-EPI) statistical copolymer with high ionic conductivity and cellulose nanofibers (CNFs), a filler with extraordinary stiffness sourced from abundant cellulose. CNF-reinforcement of EO-co-EPI increases the storage modulus up to three orders of magnitude while essentially maintaining the SPE's high ionic conductivity. The composite SPE exhibits good cycling ability and electrochemical stability, demonstrating its utility in lithium metal batteries.

Enhanced Electrochemical Performance of PEO-Based Composite Polymer Electrolyte with Single-Ion Conducting Polymer Grafted SiO2 Nanoparticles

In order to enhance the electrochemical performance and mechanical properties of poly(ethylene oxide) (PEO)-based solid polymer electrolytes, composite solid electrolytes (CSE) composed of single-ion conducting polymer-modified SiO₂, PEO and lithium salt were prepared and used in lithium-ion batteries in this work. The pyridyl disulfide terminated polymer (py-ss-PLiSSPSI) is synthesized through RAFT polymerization, then grafted onto SiO₂ via thiol-disulfide exchange reaction between SiO₂-SH and py-ss-PLiSSPSI. The chemical structure, surface morphology and elemental distribution of the as-prepared polymer and the PLiSSPSI-g-SiO₂ nanoparticles have been investigated. Moreover, CSEs containing 2, 6, and 10 wt% PLiSSPSI-g-SiO₂ nanoparticles (PLi-g-SiCSEs) are fabricated and characterized. The compatibility of the PLiSSPSI-g-SiO₂ nanoparticles and the PEO can be effectively improved owing to the excellent dispersibility of the functionalized nanoparticles in the polymer matrix, which promotes the comprehensive performances of PLi-g-SiCSEs. The PLi-g-SiCSE-6 exhibits the highest ionic conductivity (0.22 mS·cm^-1) at 60 °C, a large t_Li+ of 0.77, a wider electrochemical window of 5.6 V and a rather good lithium plating/stripping performance at 60 °C, as well as superior mechanical properties. Hence, the CSEs containing single-ion conducting polymer modified nanoparticles are promising candidates for all-solid-state lithium-ion batteries.

Insights into the use of polyepichlorohydrin polymer in lithium battery energy storage/conversion devices: review

Abstract

In this paper, the up-to-date state of polyepichlorohydrin-based electrolytes is reviewed. Research works are persistently ongoing to develop free-standing solid polymer electrolytes with exceptional performances and stabilities that can suit the needs of present and next-generation technologies. Polyepichlorohydrin (PECH), for example, is one of the polymer hosts under consideration due to its ether electron donor groups that deliver coordinating spots for cation transport as well as alkyl chloride groups for changing its surface character. Because of this structure, PECH has certain incredible characteristics including small glass transition temperature (Tg), tremendous flexibility, as well as the power to form complexation with diverse salts. Furthermore, the alkyl chloride groups serve as a location for surface modification of the polymer via nucleophilic substitution reactions, resulting in surface changes or bulk properties. As a result, the PECH in chemically modified or pristine form is an emerging option that has been researched and is being considered for use in energy storage devices. This paper reviews the latest studies on the improvements of PECH-based electrolytes for lithium-based battery storage systems. The synthesis methods of PECH polymer, types of lithium batteries, and opportunities and challenges of lithium batteries have been presented briefly. Findings on PECH-based electrolytes have been presented and discussed thoroughly. Lastly, the paper presents, battery performance needs, and cation transportation mechanisms as well as future prospects for the advancement of PECH electrolytes in the field of storage systems.

Article Highlights

UV-derived double crosslinked PEO-based solid polymer electrolyte for room temperature

The low ionic conductivity at room temperature and poor dimensional stability at high temperature of polyethylene oxide (PEO)-based solid electrolytes greatly limit the development and utilization of solid polymer electrolytes (SPEs). To reconcile the contradiction between electrochemical performance and mechanical strength of PEO-based SPEs, a cross-linking structure with active -CH2CH2O- soft chains that doped with rigid segments is designed and prepared through a method of green ultraviolet irradiation without solvent. The obtained solid film shows a high ionic conductivity of 0.2 mS·cm-1 and an ionic transference number of 0.51 at room temperature. The activation energy value of 1.92 kJ·mol-1 gives evidence for a favorable migration mechanism of PTP-SPE. A combination of flexibility and strength can be realized by molecular structure design with a tensile elongation of 40%. The reversible overpotential in galvanostatic cycling over 500 h of a Li||Li symmetrical cell indicates that the compact PTP-SPE can inhibit the formation of lithium dendrites. This work provides a new strategy for designing high-performance composite solid electrolytes at room temperature.

Recent Advances in Porous Polymers for Solid-State Rechargeable Lithium Batteries

The application of rechargeable lithium batteries involves all aspects of our daily life, such as new energy vehicles, computers, watches and other electronic mobile devices, so it is becoming more and more important in contemporary society. However, commercial liquid rechargeable lithium batteries have safety hazards such as leakage or explosion, all-solid-state lithium rechargeable lithium batteries will become the best alternatives. But the biggest challenge we face at present is the large solid-solid interface contact resistance between the solid electrolyte and the electrode as well as the low ionic conductivity of the solid electrolyte. Due to the large relative molecular mass, polymers usually exhibit solid or gel state with good mechanical strength. The intermolecules are connected by covalent bonds, so that the chemical and physical stability, corrosion resistance, high temperature resistance and fire resistance are good. Many researchers have found that polymers play an important role in improving the performance of all-solid-state lithium rechargeable batteries. This review mainly describes the application of polymers in the fields of electrodes, electrolytes, electrolyte-electrode contact interfaces, and electrode binders in all-solid-state lithium rechargeable batteries, and how to improve battery performance. This review mainly introduces the recent applications of polymers in solid-state lithium battery electrodes, electrolytes, electrode binders, etc., and describes the performance of emerging porous polymer materials and materials based on traditional polymers in solid-state lithium batteries. The comparative analysis shows the application advantages and disadvantages of the emerging porous polymer materials in this field which provides valuable reference information for further development.

Cationic polymer-in-salt electrolytes for fast metal ion conduction and solid-state battery applications

Polymer electrolytes provide a safe solution for future solid-state high-energy-density batteries. Materials that meet the simultaneous requirement of high ionic conductivity and high transference number remain a challenge, in particular for new battery chemistries beyond lithium such as Na, K and Mg. Herein, we demonstrate the versatility of a polymeric ionic liquid (PolyIL) as a polymer solvent to achieve this goal for both Na and K. Using molecular simulations, we predict and elucidate fast alkali metal ion transport in PolyILs through a structural diffusion mechanism in a polymer-in-salt environment, facilitating a high metal ion transference number simultaneously. Experimental validation of these computationally designed Na and K polymer electrolytes shows good ionic conductivities up to 1.0 × 10^-3 S cm^-1 at 80 °C and a Na⁺ transference number of ~0.57. An electrochemical cycling test on a Na∣2:1 NaFSI/PolyIL∣Na symmetric cell also demonstrates an overpotential of 100 mV at a current density of 0.5 mA cm^-2 and stable long-term Na plating/stripping performance of more than 100 hours. PolyIL-based polymer-in-salt strategies for new solid-state electrolytes thus offer an alternative route to design high-performance next-generation sustainable battery chemistries.

Progress in Solid Polymer Electrolytes for Lithium-Ion Batteries and Beyond

Solid-state polymer electrolytes (SPEs) for high electrochemical performance lithium-ion batteries have received considerable attention due to their unique characteristics; they are not prone to leakage, and they exhibit low flammability, excellent processability, good flexibility, high safety levels, and superior thermal stability. However, current SPEs are far from commercialization, mainly due to the low ionic conductivity, low Li⁺ transference number (t_Li+ ), poor electrode/electrolyte interface contact, narrow electrochemical oxidation window, and poor long-term stability of Li metal. Recent work on improving electrochemical performance and these aspects of SPEs are summarized systematically here with a particular focus on the underlying mechanisms, and the improvement strategies are also proposed. This review could lead to a deeper consideration of the issues and solutions affecting the application of SPEs and pave a new pathway to safe, high-performance lithium-ion batteries.

Development on Solid Polymer Electrolytes for Electrochemical Devices

Electrochemical devices, especially energy storage, have been around for many decades. Liquid electrolytes (LEs), which are known for their volatility and flammability, are mostly used in the fabrication of the devices. Dye-sensitized solar cells (DSSCs) and quantum dot sensitized solar cells (QDSSCs) are also using electrochemical reaction to operate. Following the demand for green and safer energy sources to replace fossil energy, this has raised the research interest in solid-state electrochemical devices. Solid polymer electrolytes (SPEs) are among the candidates to replace the LEs. Hence, understanding the mechanism of ions' transport in SPEs is crucial to achieve similar, if not better, performance to that of LEs. In this paper, the development of SPE from basic construction to electrolyte optimization, which includes polymer blending and adding various types of additives, such as plasticizers and fillers, is discussed.

From Materials to Cell: State-of-the-Art and Prospective Technologies for Lithium-Ion Battery Electrode Processing

Electrode processing plays an important role in advancing lithium-ion battery technologies and has a significant impact on cell energy density, manufacturing cost, and throughput. Compared to the extensive research on materials development, however, there has been much less effort in this area. In this Review, we outline each step in the electrode processing of lithium-ion batteries from materials to cell assembly, summarize the recent progress in individual steps, deconvolute the interplays between those steps, discuss the underlying constraints, and share some prospective technologies. This Review aims to provide an overview of the whole process in lithium-ion battery fabrication from powder to cell formation and bridge the gap between academic development and industrial manufacturing.

A study on the preparation of polycation gel polymer electrolyte for supercapacitors

The polycation gel polymer electrolyte (PGPE) is a promising electrolyte material for supercapacitors due to its high ionic conductivity and great flexibility. Herein, we report a novel flexible PGPE film, which is prepared by thermal copolymerization. The superiority of PGPE is attributed to the existence of charged groups in the polymer skeleton. Consequently, the crystallinity of the polymer is effectively reduced, and the migration of the lithium ion is evidently promoted. Moreover, the liquid retention capacity of the film is improved, which enhances its ionic conductivity as well. The reported PGPE exhibits a high ionic conductivity of 57.6 mS cm-1 at 25 °C and a potential window of 0-1.2 V. The symmetrical PGPE supercapacitor (AC/AC) shows 95.21% mass-specific capacitance retention after 5000 cycles at 2 A g-1 with a maximum energy density of 12.8 W h kg-1 and a maximum power density of 5.475 kW kg-1. This study confirms the exciting potential of PGPE for high performance supercapacitors.

Advances in Lithium-Sulfur Batteries: From Academic Research to Commercial Viability

Lithium-ion batteries, which have revolutionized portable electronics over the past three decades, were eventually recognized with the 2019 Nobel Prize in chemistry. As the energy density of current lithium-ion batteries is approaching its limit, developing new battery technologies beyond lithium-ion chemistry is significant for next-generation high energy storage. Lithium-sulfur (Li-S) batteries, which rely on the reversible redox reactions between lithium and sulfur, appears to be a promising energy storage system to take over from the conventional lithium-ion batteries for next-generation energy storage owing to their overwhelming energy density compared to the existing lithium-ion batteries today. Over the past 60 years, especially the past decade, significant academic and commercial progress has been made on Li-S batteries. From the concept of the sulfur cathode first proposed in the 1960s to the current commercial Li-S batteries used in unmanned aircraft, the story of Li-S batteries is full of breakthroughs and back tracing steps. Herein, the development and advancement of Li-S batteries in terms of sulfur-based composite cathode design, separator modification, binder improvement, electrolyte optimization, and lithium metal protection is summarized. An outlook on the future directions and prospects for Li-S batteries is also offered.

Solid Polymer Electrolyte Membranes on the Basis of Fluorosiloxane Matrix

Hydrosilylation reactions of 2,4,6,8-tetrahydro-2,4,6,8-tetramethylcyclotetrasiloxane (D4H) with 2,2,3,3,4,4,5,5-octafluoropentyl acrylate at 1:4.2 ratio of initial compounds catalysed by platinum catalysts have been studied and corresponding adduct D4R' has been obtained. Ring opening polymerization of D4R in the presence of dry potassium hydroxide has been carried out and comb-type polymers with 2,2,3,3,4,4,5,5-octafluoropentyl propionate side groups have been obtained. The synthesized product D4R and polymers were analyzed by FTIR, 1H, 13C, and 29Si NMR spectroscopy. The solid polymer electrolyte membranes have been obtained via sol-gel reactions of polymers with tetraethoxysilane doped with lithium trifluoromethylsulfonate (triflat) and lithium bis(trifluorosulfonyl)imide. It has been found that the electric conductivity of the polymer electrolyte membranes at room temperature changes in the range of (1.9•10-6) – (5.9•10-10) S•cm-1.

CNTs/LiV3O8/Y2O3 Composites with Enhanced Electrochemical Performances as Cathode Materials for Rechargeable Solid-State Lithium Metal Batteries

Solid-state lithium metal battery (SSLMB) is regarded as a safer energy storage system compared to the liquid one. The performance of the SSLMB depends on the cathode performance and the side reactions derived from the interface of the cathode and the electrolyte, which becomes much severe at high temperatures. Herein, we carried out a facile spray-drying route to prepare a CNTs/LiV₃O₈/Y₂O₃ (M-LVO-Y) composite. The synthesized cathode material exhibits an outstanding Li⁺ storage performance with a high reversible capacity of 279.9 mA h g^-1 at 0.05 A g^-1, excellent power capability (182.5 mA h g^-1 at 2 A g^-1), and a long cycle lifespan of 500 cycles with a capacity retention of 66.5% at a current density of 1 A g^-1. The fabricated rechargeable solid-state Li/M-LVO-Y-2 lithium metal battery (LMB) with a poly(ethylene oxide) (PEO)-based solid polymer electrolyte (SPE) achieves a high discharge capacity of 302.1 mA h g^-1 at 0.05 A g^-1 and a stable cycling performance with the highest capacity of 72.1% after 100 cycles at 0.2 A g^-1 and 80 °C. The above battery performance demonstrates that SSLMBs with the CNTs/LiV₃O₈/Y₂O₃ cathode and the PEO-based SPE film can provide high energy density and are suitable for applying in a high-temperature environment.

Soft Materials for Wearable/Flexible Electrochemical Energy Conversion, Storage, and Biosensor Devices

Next-generation wearable technology needs portable flexible energy storage, conversion, and biosensor devices that can be worn on soft and curved surfaces. The conformal integration of these devices requires the use of soft, flexible, light materials, and substrates with similar mechanical properties as well as high performances. In this review, we have collected and discussed the remarkable research contributions of recent years, focusing the attention on the development and arrangement of soft and flexible materials (electrodes, electrolytes, substrates) that allowed traditional power sources and sensors to become viable and compatible with wearable electronics, preserving or improving their conventional performances.

Polymer Electrolyte Membrane with High Ionic Conductivity and Enhanced Interfacial Stability for Lithium Metal Battery

Solid polymer electrolyte is one of the best choices to improve the safety of lithium metal batteries (LMBs). However, its widespread application is hindered because of the low ionic conductivity at room temperature and large interfacial resistance. Here, a cross-linked polymer is synthesized with an unsaturated polyester and used as a polymer electrolyte membrane (PEM). The PEM has a high ionic conductivity (1.99 × 10^-3 S cm^-1 at 30 °C) and a low glass transition temperature (-54.2 °C), contributing to decreasing interfacial resistance, promoting more uniform Li deposition, and suppressing Li dendrite penetration. The PEM also has a wide electrochemical stable window (∼4.6 V) and superior thermal stability (>150 °C), showing high potential in LMBs. The LiFePO₄-Li coin cells and pouch pack batteries with PEM present very stable cycle performance and high safety, indicating that the PEM can be a promising candidate for future solid-state LMBs.

Cross-linking Effects on Performance Metrics of Phenazine-Based Polymer Cathodes

Developing cathodes that can support high charge-discharge rates would improve the power density of lithium-ion batteries. Herein, the development of high-power cathodes without sacrificing energy density is reported. N,N'-diphenylphenazine was identified as a promising charge-storage center by electrochemical studies due to its reversible, fast electron transfer at high potentials. By incorporating the phenazine redox units in a cross-linked network, a high-capacity (223 mA h g^-1 ), high-voltage (3.45 V vs. Li/Li⁺ ) cathode material was achieved. Optimized cross-linked materials are able to deliver reversible capacities as high as 220 mA h g^-1 at 120 C with minimal degradation over 1000 cycles. The work presented herein highlights the fast ionic transport and rate capabilities of amorphous organic materials and demonstrates their potential as materials with high energy and power density for next-generation electrical energy-storage technologies.

Flexible, Self-Healing, and Fire-Resistant Polymer Electrolytes Fabricated via Photopolymerization for All-Solid-State Lithium Metal Batteries

The cyclophosphazene-based self-healing polymer electrolytes (CPSHPE) is designed and fabricated via the copolymerization of hexa(4-ethyl acrylate phenoxy) cyclotriphosphazene (HCP), (2-(3-(6-methyl-4-oxo-1,4-dihydropyrimidin-2-yl)ureido)ethyl methacrylate) (UPyMA), and poly(ethylene glycol) methyl ether methacrylate (PEGMA) under UV irradiation. The cross-linking structure formed by HCP could effectively enhance the mechanical strength of the polymer electrolyte, and the cyclotriphosphazene as the core is able to improve the flame-retardant properties. Benefiting from the phenyl groups in HCP and the cross-linking structure, the CPSHPE shows high thermal stability (up to 300 °C). On the other hand, the supramolecular network fabricated by the dynamic ureido-pyrimidinone (UPy) dimers endows the polymer electrolyte with good self-healing capability and is expected to improve the reliability of polymer lithium batteries. Moreover, the cells were fabricated with LiFePO₄ (LFP), CPSHPE, and Li anodes show good reversible specific capacity. The CPSHPE could be a promising candidate as the multifunctional polymer electrolyte to improve the safety performance of lithium metal batteries.

Composition Modulation and Structure Design of Inorganic-in-Polymer Composite Solid Electrolytes for Advanced Lithium Batteries

Owing to their safety, high energy density, and long cycling life, all-solid-state lithium batteries (ASSLBs) have been identified as promising systems to power portable electronic devices and electric vehicles. Developing high-performance solid-state electrolytes is vital for the successful commercialization of ASSLBs. In particular, polymer-based composite solid electrolytes (PCSEs), derived from the incorporation of inorganic fillers into polymer solid electrolytes, have emerged as one of the most promising electrolyte candidates for ASSLBs because they can synergistically integrate many merits from their components. The development of PCSEs is summarized. Their major components, including typical polymer matrices and diverse inorganic fillers, are reviewed in detail. The effects of fillers on their ionic conductivity, mechanical strength, thermal/interfacial stability and possible Li⁺ -conductive mechanisms are discussed. Recent progress in a number of rationally constructed PCSEs by compositional and structural modulation based on different design concepts is introduced. Successful applications of PCSEs in various lithium-battery systems including lithium-sulfur and lithium-gas batteries are evaluated. Finally, the challenges and future perspectives for developing high-performance PCSEs are proposed.

Towards high-performance solid-state Li-S batteries: from fundamental understanding to engineering design

Solid-state lithium-sulfur batteries (SSLSBs) with high energy densities and high safety have been considered among the most promising energy storage devices to meet the demanding market requirements for electric vehicles. However, critical challenges such as lithium polysulfide shuttling effects, mismatched interfaces, Li dendrite growth, and the gap between fundamental research and practical applications still hinder the commercialization of SSLSBs. This review aims to combine the fundamental and engineering perspectives to seek rational design parameters for practical SSLSBs. The working principles, constituent components, and practical challenges of SSLSBs are reviewed. Recent progress and approaches to understand the interfacial challenges via advanced characterization techniques and density functional theory (DFT) calculations are summarized and discussed. A series of design parameters including sulfur loading, electrolyte thickness, discharge capacity, discharge voltage, and cathode sulfur content are systematically analyzed to study their influence on the gravimetric and volumetric energy densities of SSLSB pouch cells. The advantages and disadvantages of recently reported SSLSBs are discussed, and potential strategies are provided to address the shortcomings. Finally, potential future directions and prospects in SSLSB engineering are examined.

An ionic liquid crystal-based solid polymer electrolyte with desirable ion-conducting channels for superior performance ambient-temperature lithium batteries

Almost all the traditional ionic liquids lack liquid crystal properties.

Biocompatible and biodegradable solid polymer electrolytes for high voltage and high temperature lithium batteries

Wheat flour modified solid polymer electrolytes were synthesized and used in high safety and long cycling lithium batteries.