Buffering Volume Change in Solid-State Battery Composite Cathodes with CO2-Derived Block Polycarbonate Ethers

• DOI: 10.1021/jacs.2c06138
• Publication Date: 2022-09-19T20:53:20Z
• Authors: Georgina L. Gregory; Hui Gao; Boyang Liu; Xiangwen Gao; Gregory J. Rees; Mauro Pasta; Peter G. Bruce; Charlotte K. Will...
• Keywords: Polycarbonate

Polymers designed with a specific combination of electrochemical, mechanical, and chemical properties could help overcome challenges limiting practical all-solid-state batteries for high-performance next-generation energy storage devices. In composite cathodes, comprising active cathode material, inorganic solid electrolyte, carbon, battery longevity is limited by particle volume changes occurring on charge/discharge. To this, impractical high pressures are applied to maintain interfacial contact. Herein, block polymers address these issues combine ionic conductivity, electrochemical stability, suitable elastomeric mechanical properties, including adhesion. The have "hard-soft-hard", ABA, structures, where the soft "B" poly(ethylene oxide) (PEO), known promote hard "A" CO2-derived polycarbonate, poly(4-vinyl cyclohexene oxide carbonate), which provides rigidity enhances oxidative stability. ABA featuring controllable PEO polycarbonate lengths straightforwardly prepared using hydroxyl telechelic as macroinitiator CO2/epoxide ring-opening copolymerization well-controlled Mg(II)Co(II) catalyst. influence polymer composition upon investigated, phosphonic acid functionalities being installed in domains adhesive properties. Three lead materials identified; show an ambient conductivity 10 -4 S cm-1, lithium-ion transport (tLi+ 0.3-0.62), stability (>4 V vs Li+/Li), or plastomer (G' 0.1-67 MPa). best used cathodes LiNi0.8Mn0.1Co0.1O2 material Li6PS5Cl electrolyte-the resulting solid-state demonstrate greater capacity retention than equivalent cells no commercial polyelectrolytes.