Boosting Cycling Stability of Polymer Sodium Battery by “Rigid-Flexible” Coupled Interfacial Stress Modulation

• Published in: Nano letters 2023-04, Vol.23 (8), p.3630-3636
• Main Authors: Pan, Jun, Xu, Shumao, Cai, Tianxun, Hu, Lulu, Che, Xiangli, Dong, Wujie, Shi, Zhiyuan, Rai, Alok Kumar, Wang, Nana, Huang, Fuqiang, Dou, Shi Xue
• Format: Article
• Language: English
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/acs.nanolett.2c04854

The discontinuous interfacial contact of solid-state polymer metal batteries is due to the stress changes in the electrode structure during cycling, resulting in poor ion transport. Herein, a rigid-flexible coupled interface stress modulation strategy is developed to solve the above issues, which is to design a rigid cathode with enhanced solid-solution behavior to guide the uniform distribution of ions and electric field. Meanwhile, the polymer components are optimized to build an organic–inorganic blended flexible interfacial film to relieve the change of interfacial stress and ensure rapid ion transmission. The fabricated battery comprising a Co-modulated P2-type layered cathode (Na0.67Mn2/3Co1/3O2) and a high ion conductive polymer could deliver good cycling stability without distinct capacity fading (72.8 mAh g–1 over 350 cycles at 1 C), outperforming those without Co modulation or interfacial film construction. This work demonstrates a promising rigid-flexible coupled interfacial stress modulation strategy for polymer–metal batteries with excellent cycling stability.