期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2016
卷号：113
期号：47
页码：13313-13317
DOI：10.1073/pnas.1615912113
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：SignificanceRealization of a safe, low-cost rechargeable lithium battery of high energy density and long cycle life is needed for powering an electric road vehicle and for storing electric power generated by solar or wind energy. This urgent need has prompted efforts to develop a solid electrolyte with an alkali metal anode. Only now is it recognized that the key requirement is wetting of the electrolyte surface by the alkali-metal anode. We report a full rechargeable cell with a solid electrolyte that, although it is reduced by metallic lithium, forms a thin lithium-electrolyte interface that is wet by the anode and wets the electrolyte to give a small Li+ transfer resistance across the interface. A solid electrolyte with a high Li-ion conductivity and a small interfacial resistance against a Li metal anode is a key component in all-solid-state Li metal batteries, but there is no ceramic oxide electrolyte available for this application except the thin-film Li-P oxynitride electrolyte; ceramic electrolytes are either easily reduced by Li metal or penetrated by Li dendrites in a short time. Here, we introduce a solid electrolyte LiZr2(PO4)3 with rhombohedral structure at room temperature that has a bulk Li-ion conductivity{sigma} Li = 2 x 10-4 S*cm-1 at 25 {degrees}C, a high electrochemical stability up to 5.5 V versus Li+/Li, and a small interfacial resistance for Li+ transfer. It reacts with a metallic lithium anode to form a Li+-conducting passivation layer (solid-electrolyte interphase) containing Li3P and Li8ZrO6 that is wet by the lithium anode and also wets the LiZr2(PO4)3 electrolyte. An all-solid-state Li/LiFePO4 cell with a polymer catholyte shows good cyclability and a long cycle life.
