A Highly Salt-Soluble Ketone-Based All-Solid-State Polymer Electrolyte with Superior Performances for Lithium-Ion Batteries.

Solid polymer electrolytes (SPEs) have great potential to be used in high-safety lithium-ion batteries (LIBs). However, it is still a significant challenge for SPEs to develop high ionic conductivity, high mechanical strength, and good interior interfacial compatibility. In this work, a ketone-based all-solid-state electrolyte (PAD) resulting from allyl acetoacetate (AAA), diacetone acrylamide (DAAM), and poly(ethylene glycol) diacrylate (PEGDA) was prepared by UV-inducing photopolymerization. The abundant ketone groups endow the prepared PAD all-solid-state electrolyte with strong dissociation of lithium salts and weak coordination interactions between ketone groups and Li. Depending on the unique properties of the ketone groups in the electrolyte system, the prepared polymer electrolytes show a high lithium-ion transference number of 0.87 and a wide electrochemical window of 4.95 V. Furthermore, the PAD electrolyte also exhibits superior viscoelasticity, which is beneficial for good contact with electrodes. As a result, the assembled LFP/PAD/Li cells with PAD electrolytes show good cycle performance and rate performance. Concretely, the all-solid-state symmetric lithium cells with the PAD electrolyte can achieve stable lithium plating and stripping at 0.05 mA cm for over 1000 h at 60 °C. This work highlights the advantages of ketone-based electrolyte as a polymer electrolyte and provides a design method for advanced polymer electrolytes applied in high-performance solid lithium batteries.