LiMnO (LMO) is a key component in lithium-rich manganese-based oxides (LMROs) and has attracted great attention as a cathode for lithium-ion batteries (LIBs) due to its high theoretical capacity and cost-effectiveness. However, its severe capacity fading and discharge voltage decay during prolonged cycling greatly hinders its applications. In this study, an LMO film is prepared, followed by the fabrication and investigation of an LMO/LiPON/Li all-solid-state thin film lithium battery (LMO-TFLB). The results show that although the LiPON electrolyte deposition results in the formation of a disordered interface layer derived from the LMO layer, an LMO/LiPON interface with small interfacial resistance and good structural stability during cycling is obtained, allowing fast Li diffusion across the interface. Furthermore, in contrast to the half cell that uses liquid electrolyte (LMO-LIB), the LiPON electrolyte in the LMO-TFLB significantly aids in impeding the Mn dissolution to prevent active material loss. More importantly, although a structural transformation from a layered LMO phase to a spinel-like phase occurs in the cathode of the LMO-TFLB during cycling, the transformed spinel-like phase with a higher crystallinity than that in the LMO-LIB facilitates fast Li and electron transport to improve the LMO-TFLB's capacity. Consequently, the LMO-TFLB exhibits a long cycle life without any capacity loss after 1000 cycles, which outperforms that of the LMO-LIB (20% capacity retention after 450 cycles). This work demonstrates that all-solid-state battery configuration is highly promising for unlocking the full potential of LMROs cathode materials for LIBs.

中文翻译：

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全固态电池配置实现长循环寿命的Li2MnO3薄膜正极

LiMnO（LMO）是富锂锰基氧化物（LMRO）的关键成分，由于其高理论容量和成本效益，作为锂离子电池（LIB）的阴极而受到广泛关注。然而，其在长时间循环过程中严重的容量衰减和放电电压衰减极大地阻碍了其应用。在本研究中，制备了 LMO 薄膜，然后制造和研究了 LMO/LiPON/Li 全固态薄膜锂电池（LMO-TFLB）。结果表明，虽然LiPON电解质沉积导致形成源自LMO层的无序界面层，但获得了界面电阻小且循环过程中结构稳定性良好的LMO/LiPON界面，允许Li在界面上快速扩散。此外，与使用液体电解质的半电池 (LMO-LIB) 相比，LMO-TFLB 中的 LiPON 电解质显着有助于阻止 Mn 溶解，从而防止活性材料损失。更重要的是，虽然在循环过程中LMO-TFLB的阴极发生了从层状LMO相到类尖晶石相的结构转变，但转变后的类尖晶石相具有比LMO-LIB更高的结晶度，有利于快速Li和电子传输以提高 LMO-TFLB 的容量。因此，LMO-TFLB 表现出较长的循环寿命，1000 次循环后没有任何容量损失，优于 LMO-LIB（450 次循环后容量保持率为 20%）。这项工作表明，全固态电池配置对于释放 LMRO 锂离子电池正极材料的全部潜力非常有前景。