In-situ fabricated succinonitrile-based composite electrolyte for high-performance and safe solid-state lithium batteries

The succinonitrile (SN) plastic crystal electrolyte with excellent comprehensive properties such as high room temperature (RT) ionic conductivity, wide electrochemical window and low cost, making it a promising candidate for RT solid-state lithium batteries (SSLBs). However, severe spontaneous chemical reactions between SN and active Li anode cause serious damage to the electrolyte/electrode interface, which still needs to be further improved. In this work, an in-situ polymerized SN-based composite solid-state electrolyte (CSE) is exploited to conquer the severe side-reactions between SN-based electrolyte and Li anode, the PALA0.5@-CSE (polyacrylonitrile (PAN): modified-Lil.3Al0.3Til.7(PO4)3 (LATP@) = 1:0.5, w/w) demonstrates an outstanding ionic conductivity (0.45 mS cm−1), high electrochemical stability (5.1 V) and improved Li+ transference number (0.67) at RT. The Li symmetric cells with PALA0.5@-CSE shows a high critical current density (CCD) of 1.2 mA cm−2, and the Li symmetric cells deliver excellent cycle stability over 500 h, demonstrating the superior ability of PALA0.5@-CSE to suppress the side-reactions between SN and Li anode and the rapid growth of Li dendrite. In Li||LiFePO4(LFP) full cell, the SSLBs provide excellent RT rate capability and stable cycling performance. Moreover, the PALA0.5@-CSE possesses high thermal stability and incombustibility, demonstrating its superior safety for the future utilization of SN-based SSLBs.