Composition regulation of polyacrylonitrile-based polymer electrolytes enabling dual-interfacially stable solid-state lithium batteries

The polyacrylonitrile (PAN) is an attractive matrix of polymer electrolytes owing to its wide electrochemical window and strong coordination with Li salts. However, the PAN -based electrolytes undergo severe interfacial problems from both cathode and anode sides, including uneven ionic transfer induced by high rigidity of dry PAN -based polymer, as well as inferior stability against Li -metal anode. Herein, the composition regulation of PAN -based electrolytes is proposed by introducing succinonitrile (SN) plastic crystal and LiNO 3 salt for the construction of interfacially stable solid-state lithium batteries. The plastic nature of SN enables the rapid ionic transfer in electrolytes, along with the establishment of conformally interfacial contacts. Meanwhile, a stable solid -electrolyte -interface (SEI) layer consisting of Li 3 N and LiNO 2 is in -situ formed at Li/electrolyte interface, contributing to the inhibition of uncontrol reactions between PAN and Li -metal. Consequently, the resultant Li symmetric cell delivers an extended critical current density of 1.7 mA cm -2 and an outstanding cycling lifespan of 700 h at 0.1 mA cm -2 . Moreover, the corresponding solid-state LiNi 0.6 Co 0.2 Mn 0.2 O 2 /Li full cell shows an initial discharge capacity of 161 mAh/g followed by an outstanding capacity retention of 88.7 % after 100 cycles at 0.1C. This work paves the way for application of PAN -based electrolytes in the field of solid-state batteries by facile composition regulation.