High-Safety All-Solid-State Lithium-Ion Battery Working at Ambient Temperature with In Situ UV-Curing Polymer Electrolyte on the Electrode

Graphical Wearable ASSLIB : In situ polymerization on the electrode can enhance the adhesion between the electrode and the electrolyte, resulting in enhanced cycle and rate performance of all-solid-state lithium-ion batteries (ASSLIBs). The development of wearable electronic devices prompts the demand for high-safety all-solid-state lithium-ion batteries (ASSLIBs), which can work at ambient temperature with comparable performance to traditional commercial lithium-ion batteries. In this work, a three-dimensional network design to overcome the contradiction between ionic conductivity and mechanical strength in polymer electrolytes is proposed. The designed solid polymer electrolyte (SPE) has the ion-conducting group (oligomeric ethylene oxide) fixed on the side chains, whereas the main chain is crosslinked polyacrylate, providing good mechanical strength. Succinonitrile (SN) is uniformly dispersed in the cross-linked network as an additive. The prepared SN−SPE shows a high ionic conductivity of 4.6×10 −4 S cm −1 at 25 °C with a Li + -ion transference number of 0.45 and an excellent electrochemical stability window up to 4.6 V (vs. Li + /Li). The preparation method allows that the electrolyte can be UV-cured in situ on the cathode to achieve a cathode-electrolyte integrated electrode, which enhances the interface contact and decreases the interface resistance. As-fabricated LiFePO 4 //Li 4 Ti 5 O 12 cathode-electrolyte integrated ASSLIBs can deliver a discharge capacity of 155.88 mAh g −1 at 0.2 C at room temperature and a capacity retention up to 93.62 % after 100 charge-discharge cycles. The reported polymer electrolyte and advanced assembly process provided a promising strategy for the wearable ASSLIBs.