Semiconductor waste-derived LiGaO2: A multifunctional regulator for crystallization, ion transport, and stability in polymer electrolytes

Abstract

Succinonitrile (SN)-based composite polymer electrolytes offer high ionic conductivity and flexibility for solid-state lithium metal batteries (SSLMBs); however, they suffer from cyano group-induced interfacial side reactions and PVDF's crystallinity-driven performance limitations. Herein, we introduce semiconductor waste-derived LiGaO2 (LGO) as a multifunctional additive to address these challenges. LGO's high-dielectric constant modulates PVDF-HFP crystallization into disordered amorphous domains, reducing interfacial resistance and enhancing exchange current density. Simultaneously, LGO promotes LiTFSI dissociation via dipole interactions while anchoring SN molecules, suppressing migration and side reactions. The optimized electrolyte achieves an ionic conductivity of 1.24 × 10−3 S·cm−1, a transference number of 0.67, an activation energy of 0.13 eV, and a critical current density of 0.8 mA·cm−2 at 45 °C. Symmetric Li cells show stable cycling, while LiCoO2/Li batteries exhibit superior rate performance (111.8 mAh·g−1 at 2 C) and retain 61.4% capacity after 100 cycles at 0.5 C with 99.2% average Coulombic efficiency. These findings reveal the core mechanism of high-dielectric constant nanomaterials in regulating crystallization kinetics and promoting internal ionic transport in multicomponent polymer electrolytes, providing new directions for the development of SSLMBs.