20 µm Li metal modified with phosphate rich polymer-inorganic interphase applied in commercial carbonate electrolyte

Li metal batteries are supposed to reach real application in order to fulfill the high-energy density requirement of energy storage system. Unfortunately, the commonly used carbonate electrolyte react with pristine Li, which result in short lifetime of lithium metal battery. To alleviate the side reactions of Li metal with liquid electrolyte, here we propose a phosphate rich polymer-inorganic layer as an interphase. Due to the inert properties of lithium phosphate derived from LiPO2F2 and poly-ether, the side-reaction of carbonate solvent are prevented. As a result, lithium metal anode sustains for 800 cycles in symmetrical cell test under 1 mA cm−2. Even under strict condition (20 µm Li, capacity ratio N/P = 2.3, electrolyte/active material = 3 µL mg−1), coin cell test still runs stable for 150 cycles with high Coulombic efficiency. Furthermore, both LiFePO4 and LiNi0.8Co0.1Mn0.1O2 pouch cell under 5 µL mA−1 h−1 condition also exhibit good stability at 0.5 C and 2 C rate. With this approach, high-energy and high-power Li metal batteries are approaching to real application in the near future.