Rigid–Flexible Coupling Polymer Electrolytes toward High‐Energy Lithium Batteries

Abstract

Polymer electrolytes have aroused wide interest in lithium batteries, but their comprehensive performances (including ionic conductivity, electrochemical window, and mechanical strength) need to be enhanced for high‐energy lithium batteries. A rigid–flexible coupling strategy is proposed to enhance the comprehensive performances of polymer electrolytes. To date, “rigid–flexible coupling” has been widely applied in gel and solid polymer electrolytes. For many kinds of polymer electrolytes, their ionic conductivity, electrochemical window, interfacial stability, and mechanical properties are significantly improved by “rigid–flexible coupling,” breaking their inherent application barriers in high‐energy lithium battery. Herein, recent key progress in rigid–flexible coupling polymer electrolytes is reviewed in terms of their design concepts, chemical‐physical properties, electrochemical performances, and battery properties. This overview also conducts a perspective for rigid–flexible coupling polymer electrolytes. It is hoped that fresh and established researchers can obtain a clear perspective of “rigid–flexible coupling” and this mini review can also throw light on the exploration of high‐energy polymer lithium batteries.

Effects of gelation behavior of PPC-based electrolyte on electrochemical performance of solid state lithium battery

“…In order to improve the mechanical strength of the PPC solid film, a commercial cellulose membrane was used as a support skeleton for the PPC solid film [13,18,19]. The entirepreparation process was shown in Fig.…”

“…Compared with the most studied PEO solid electrolytes [8], PC-based solid electrolytes have obvious advantages [6,7,[12][13][14][15][16][17][18][19]: (1) RT conductivity can reach 10 −4 S cm −1 or more; (2) The electrochemical window can reach more than 4 V; (3) The ion migration number can reach 0.5 or more. These advantages are the focus of the electrochemical performance of SPE.…”

Recent Progress in Organic–Inorganic Composite Solid Electrolytes for All‐Solid‐State Lithium Batteries

“…Compared with SPEs and ISEs, organic-inorganic CSEs possess outstanding mechanical properties, high ionic conductivity,a nd good interfacial stability. [14] Thus, developing organic-inorganic CSEs with remarkable performance appearst ob e an attractive research topic and might be an effective strategy for improving the performance of advanced ASSBs. [15] To date, av ariety of organic-inorganic CSEsh aveb een reported.…”

“…Organic–inorganic CSEs are generally composed of the polymer matrix, inorganic inert ceramic fillers, or ceramic fast ionic conductor, which can integrate the merits of polymers and inorganic electrolytes. Compared with SPEs and ISEs, organic–inorganic CSEs possess outstanding mechanical properties, high ionic conductivity, and good interfacial stability . Thus, developing organic–inorganic CSEs with remarkable performance appears to be an attractive research topic and might be an effective strategy for improving the performance of advanced ASSBs .…”

Manufacturing Strategies for Solid Electrolyte in Batteries

“…As one key component for the practical application of solid-state batteries, SSEs have demonstrated numerous advantages over the organic liquid electrolyte: (i) the characteristics of non-flammability, high-temperature stability, and non-volatilization to eliminate the combustion or explosion of organic liquid electrolytes (Fergus, 2010;Takada, 2013;Sun et al, 2020), (ii) a wide electrochemical window to enable better compatibility with a higher-potential cathode, which greatly improves the energy density (Judez et al, 2017;Wang et al, 2018), (iii) an improved mechanical rigidity (especially for ISEs) to suppress dendrite growth from cycled metallic anodes (Goodenough and Singh, 2015;Kim J.G. et al, 2015), and (iv) a tunable elastic modulus (especially for SPEs and CSEs) allowing for a higher degree of processability and flexibility (Yue et al, 2016;Lau et al, 2018;Schnell et al, 2018;Zhou et al, 2018). However, several challenges should be further investigated and addressed: (i) the low ionic conductivity (<10 −5 S cm −1 for SPEs and <10 −3 S cm −1 for ISEs) compared with the liquid electrolyte (>10 −3 S cm −1 ) that leads to a low power rate, and (ii) the difficulty in manufacturing miniature/large ISEs with high brittleness.…”