In this review, state-of-the-art polymer electrolytes are discussed with respect to their electrochemical and physical properties for their application in lithium polymer batteries. We divide polymer electrolytes into the two large categories of solid polymer electrolytes and gel polymer electrolytes (GPE). The performance requirements and ion transfer mechanisms of polymer electrolytes are presented at first. Then, solid polymer electrolyte systems, including dry solid polymer electrolytes, polymer-in-salt systems (rubbery electrolytes), and single-ion conducting polymer electrolytes, are described systematically. Solid polymer electrolytes still suffer from poor ionic conductivity, which is lower than 10−5 S cm−1. In order to further improve the ionic conductivity, numerous new types of lithium salt have been studied and inorganic fillers have been incorporated into solid polymer electrolytes. In the section on gel polymer electrolytes, the types of plasticizer and preparation methods of GPEs are summarized. Although the ionic conductivity of GPEs can reach 10−3 S cm−1, their low mechanical strength and poor interfacial properties are obstacles to their practical application. Significant attention is paid to the incorporation of inorganic fillers into GPEs to improve their mechanical strength as well as their transport properties and electrochemical properties.

Polymer electrolytes for lithium polymer batteries

As one important component of sulfur cathodes, the carbon host plays a key role in the electrochemical performance of lithium-sulfur (Li-S) batteries. In this paper, a mesoporous nitrogen-doped carbon (MPNC)-sulfur nanocomposite is reported as a novel cathode for advanced Li-S batteries. The nitrogen doping in the MPNC material can effectively promote chemical adsorption between sulfur atoms and oxygen functional groups on the carbon, as verifi ed by X-ray absorption near edge structure spectroscopy, and the mechanism by which nitrogen enables the behavior is further revealed by density functional theory calculations. Based on the advantages of the porous structure and nitrogen doping, the MPNC-sulfur cathodes show excellent cycling stability (95% retention within 100 cycles) at a high current density of 0.7 mAh cm −2 with a high sulfur loading (4.2 mg S cm −2 ) and a sulfur content (70 wt%). A high areal capacity (≈3.3 mAh cm −2 ) is demonstrated by using the novel cathode, which is crucial for the practical application of Li-S batteries. It is believed that the important role of nitrogen doping promoted chemical adsorption can be extended for development of other high performance carbon-sulfur composite cathodes for Li-S batteries.

Nitrogen-Doped Mesoporous Carbon Promoted Chemical Adsorption of Sulfur and Fabrication of High-Areal-Capacity Sulfur Cathode with Exceptional Cycling Stability for Lithium-Sulfur Batteries

Solid-state batteries have been attracting wide attention for next generation energy storage devices due to the probability to realize higher energy density and superior safety performance compared with the state-of-the-art lithium ion batteries. However, there are still intimidating challenges for developing low cost and industrially scalable solid-state batteries with high energy density and stable cycling life for large-scale energy storage and electric vehicle applications. This review presents an overview on the scientific challenges, fundamental mechanisms, and design strategies for solid-state batteries, specifically focusing on the stability issues of solid-state electrolytes and the associated interfaces with both cathode and anode electrodes. First, we give a brief overview on the history of solid-state battery technologies, followed by introduction and discussion on different types of solid-state electrolytes. Then, the associated stability issues, from phenomena to fundamental understandings, are intensively discussed, including chemical, electrochemical, mechanical, and thermal stability issues; effective optimization strategies are also summarized. State-of-the-art characterization techniques and in situ and operando measurement methods deployed and developed to study the aforementioned issues are summarized as well. Following the obtained insights, perspectives are given in the end on how to design practically accessible solid-state batteries in the future.

Approaching Practically Accessible Solid-State Batteries: Stability Issues Related to Solid Electrolytes and Interfaces

Thermal issues about Li-ion batteries and recent progress in battery thermal management systems: A review

Introduction Lithium-sulfur batteries are considered as a promising candidate for next-generation secondary batteries because of their high theoretical capacit y, safe operating voltage (2.15 V vs. Li/Li ), and low cost. Nevertheless, lithium-sulfur batteries suffer from capacity fading, which limits their widespread application, due to the insulating nature of sulfur and its reduced pro ducts and the dissolution of intermediate lithium polysul fides. To address these problems, carbon-based materials have been integrated with sulfur to enhance the conductivity and inhibit the polysulfide dissolutio n. Recently, graphene, a single-atom-thick carbon mate rial with superior electrical conductivity and mechanica l flexibility, has been successfully applied in lithi um-sulfur batteries. While graphene-sulfur composite cathodes  demonstrate promising electrochemical performance, their synthesis is usually complicated and challeng ing for large-scale application. On the other hand, the sol utionbased synthesis without heat treatment produces lar ge crystalline sulfur particles, resulting in low util ization of active materials and poor rate performance. Herein, we report hydroxylated graphene nanosheets as a substr ate to produce graphene-amorphous sulfur nanocomposites, exhibiting superior cyclability at high rates, by a facile in situ deposition method at room temperature.

Hydroxylated Graphene-Sulfur Nanocomposites for High-Rate Lithium-Sulfur Batteries

Investigations on the effect of various plasticizers in PVA–PMMA solid polymer blend electrolytes

Effect of salt concentration in poly(vinyl alcohol)-based solid polymer electrolytes

Li-ion conduction of plasticized PVA solid polymer electrolytes complexed with various lithium salts

http://ntur.lib.ntu.edu.tw/bitstream/246246/92334/1/33.pdf

Rengapillai Subadevi

Papers

Investigations on the effect of various plasticizers in PVA–PMMA solid polymer blend electrolytes

Effect of salt concentration in poly(vinyl alcohol)-based solid polymer electrolytes

Li-ion conduction of plasticized PVA solid polymer electrolytes complexed with various lithium salts

Compositional effect of PVdF-PEMA blend gel polymer electrolytes for lithium polymer batteries

Electrochemical studies on [(1 − x)PVA–xPMMA] solid polymer blend electrolytes complexed with LiBF4