A Single‐Pot Co‐Precipitation Synthesis Route for Ni‐Rich Layered Oxide Materials with High Cycling Stability
Harald Norrud Pollen, Julian R. Tolchard, Ann Mari Svensson, Nils P. Wagner
Abstract
Abstract In this work we report variations of LiNi 0.88 Mn 0.06 Co 0.06 O 2 synthesised through a single‐pot oxalic acid co‐precipitation route, in which all cation precursors were added in the same step. The effects of Al‐doping, heat‐treatment temperature and Li precursor excess were investigated with physicochemical and electrochemical characterisation. Phase pure and well‐ordered polycrystalline materials were successfully synthesised for all Al‐doped and undoped compositions. Undoped LiNi 0.88 Mn 0.06 Co 0.06 O 2 prepared at 750 °C with 4 at% excess Li precursor showed excellent cycling stability in NMC||LTO cells with an initial capacity of 201 mAh/g at 0.1 C at 20 °C, and a capacity retention of 81 % after 415 cycles. The Al‐doped variations LiNi 0.88 Mn 0.04 Co 0.06 Al 0.02 O 2 and LiNi 0.88 Mn 0.06 Co 0.04 Al 0.02 O 2 were synthesised, and they showed similar initial electrochemical performance to undoped LiNi 0.88 Mn 0.06 Co 0.06 O 2 , but Al‐doping via the oxalic acid co‐precipitation route resulted in shorter cycle life. The study outlines the importance of the processing parameters to achieve Ni‐rich layered oxides with a long cycle life without further surface modifications.