The all-solid-state lithium battery (ASSLB) with lithium-rich manganese oxide (LRMO) cathode material is one of the strongest competitors for the next generation energy-storage device with high energy density. However, due to the serious interfacial reaction between LRMO and halide solid-state electrolyte (SSE), its electrochemical performance cannot meet the practical demand. In this work, in-situ electrochemical impedance spectroscopy (EIS), X-ray photoelectron spectroscopy (XPS) tests and high resolution transmission electron microscope (HR-TEM) are carried out to clarify the interfacial reaction mechanism between LRMO and Li 3 InCl 6 (LIC). The active oxygen released from LRMO and phase transition of LRMO are confirmed to seriously deteriorate the LRMO/LIC interface. To solve the above problems, a uniform LiNbO 3 coating is introduced to alleviate the interfacial side reaction and phase transition of LRMO. With moderate coating amount (1.5 wt%, ∼10 nm thick), the LNO@LRMO cathode shows an initial discharge capacity of 185 mA h g − 1 with 67% capacity retention after 100 cycles in halide-based ASSLB, which greatly exceeds that of bare LRMO cathode under voltage range of 2.3–4.8 V. This work provides a new perspective for improving the performance of LRMO in halide-based ASSLBs to achieve high energy density.
In order to obtain high power density, energy density and safe energy storage lithium ion batteries (LIB) to meet growing demand for electronic products, oxide cathodes have been widely explored in all-solid-state lithium batteries (ASSLB) using sulfide solid electrolyte. However, the electrochemical performances are still not satisfactory, due to the high interfacial resistance caused by severe interfacial instability between sulfide solid electrolyte and oxide cathode, especially Ni-rich oxide cathodes, in charge-discharge process. Ni-rich LiNi 0.8 Co 0.1 Mn 0.1 O 2 (NCM811) material at present is one of the most key cathode candidates to achieve the high energy density up to 300 Wh kg −1 in liquid LIB, but rarely investigated in ASSLB using sulfide electrolyte. To design the stable interface between NCM811 and sulfide electrolyte should be extremely necessary. In this work, in view of our previous work, LiNbO 3 coating with about 1 wt% content is adopted to improve the interfacial stability and the electrochemical performances of NCM811 cathode in ASSLB using Li 10 GeP 2 S 12 solid electrolyte. Consequently, LiNbO 3 -coated NCM811 cathode displays the higher discharge capacity and rate performance than the reported oxide electrodes in ASSLB using sulfide solid electrolyte to our knowledge.