Hybrid Dynamic Covalent Network-Based Protecting Layer for Stable Li-Metal Batteries

• DOI: 10.1021/acsami.3c15690
• Publication Date: 2024-02-28T08:38:02Z
• Authors: Hao Feng; Yayue He; Mengxiang Ma; Shilun Gao; Sheng Zhao; Xinyuan Shan; Huabin Yang; Peng-Fei Cao

Metallic lithium (Li) is considered as the "Holy Grail" anode material for next-generation energy storage systems due to its extremely high theoretical capacity and low electrochemical potential. Before commercialization of Li electrode, dendritic growth unstable solid electrolyte interphase layer should be conquered. Herein, a hybrid covalent adaptable polymer network (HCAPN) prepared via random copolymerization poly(ethylene glycol) methyl ether methacrylate -acetoacetoxyethyl methacrylate, followed by chemical cross-linking with polyethylenimine (PEI) amine-modified silicon dioxide (SiO2). Such network, where PEI SiO2 formed vinylogous urethane-based dynamic bond copolymer, respectively, shows improved mechanical properties, solvent resistance, excellent healability/recyclability. As protecting on assembled HCAPN@Li||HCAPN@Li symmetric cell long cycle life 800 h overpotential at current density 1 mA cm–2, superior performance can achieved in HCAPN@Li||LiFePO4 full (capacity retention 77% over 400 cycles 1.5 C) HCAPN@Li||NCM811 79% after 300 cycles). Surface morphology analysis also performed physical insight into their role layer. This work provides new perspective constructing network-based inhibiting dendrite growth.