High‐performance solid PEO/PPC/LLTO‐nanowires polymer composite electrolyte for solid‐state lithium battery

Solid polymer composite electrolyte (SPCE) with good safety, easy processability, and high ionic conductivity was a promising solution to achieve the development of advanced solid-state lithium battery. Herein, through electrospinning and subsequent calcination, the Li0.33La0.557TiO3 nanowires (LLTO-NWs) with high ionic conductivity were synthesized. They were utilized to prepare polymer composite electrolytes which were composed of poly (ethylene oxide) (PEO), poly (propylene carbonate) (PPC), lithium bis (fluorosulfonyl)imide (LiTFSI), and LLTO-NWs. Their structures, thermal properties, ionic conductivities, ion transference number, electrochemical stability window, as well as their compatibility with lithium metal, were studied. The results displayed that the maximum ionic conductivities of SPCE containing 8 wt.% LLTO-NWs were 5.66 × 10−5 S cm−1 and 4.72 × 10−4 S cm−1 at room temperature and 60°C, respectively. The solid-state LiFePO4/Li cells assembled with this novel SPCE exhibited an initial reversible discharge capacity of 135 mAh g−1 and good cycling stability at a charge/discharge current density of 0.5 C at 60°C.