Compared to currently commercialized lithium-ion batteries, which use flammable organic liquid electrolytes and low-energy-density graphite anodes, solid-state lithium-metal batteries (SSLMBs) offer enhanced energy density and improved safety, making them promising alternatives for next-generation rechargeable batteries.[1] As a crucial component of these batteries, solid-state electrolytes–divided into inorganic solid ceramic electrolytes (SCEs) and organic solid polymer electrolytes (SPEs)–are vital for lithium-ion transport and inhibiting lithium dendrite growth. Among them, SCEs exhibit high ionic conductivity, excellent mechanical properties, and outstanding electrochemical and thermal stability. Nevertheless, their brittleness, interfacial challenges with electrodes, and the requirement for high stacking pressure during battery operation significantly hinder their scalable application. In comparison, SPEs are more favourable for manufacturing due to their flexibility and good interfacial compatibility with electrodes.[2] Despite these advantages, SPEs still face significant challenges in achieving practical application. Firstly, typical SPEs, such as poly(ethylene oxide) (PEO), Poly(vinylidene fluoride) (PVDF), and Poly(ethylene glycol)diacrylate (PEGDA), are characterized by high crystallinity, which causes polymer chains to be tightly packed and rigid. This restricts the segmental motion within the SPEs, resulting in low ionic conductivity. Secondly, compared to lithium ions, anions with large ionic radius and low charge density typically form weaker interactions with the polymer chains, which facilitates their mobility and results in a low lithium-ion transport number (t+). Thirdly, the weak interactions between polymer chains in typical SPEs lead to a low elastic modulus, which in turn compromising their poor mechanical strength.