PEO-based electrolyte filled with UV-cured 3D cross-linked polymer network for lithium metal batteries

In order to solve the problems of low ionic conductivity, low lithium-ion transference number and weak mechanical strength of PEO solid polymer electrolytes (SPEs), this paper proposes to prepare composite cross-linked network polymer electrolytes (PEO-AAEM) through UV crosslinked polymerization of allyl acetoacetate (AAEM) and N-N-methylene diacrylamide (MBA) within the PEO SPEs. The amide group within the cross-linked network facilitates the dissociation of Li+, while the carbonyl group serves as a conduit for Li+ transport. The PEO-AAEM SPEs exhibit the ionic conductivity of 5.4x10-4 S cm-1, with a lithium-ion transference number of 0.54 at 60 degrees C. The assembled Li//Li battery with proper AAEM content can be stably cycled for 2000 h at 0.2 mA cm-2 current, and LiFePO4//Li battery maintains a reversible capacity of 100 mA h g-1 after 500 cycles at 0.2C. This work offers a viable pathway for developing SPEs with improved electrochemical performance for all solid-state lithium metal batteries (ASSLMBs).