Department of Physics and Electronic Information Engineering, Qinghai Nationalities University, No.3 Bayizhonglu, Chengdong District, Xining 810007, China.
Pen-Tung Sah Institute of Micro-Nano Science and Technology, Xiamen University, Xiamen 361005, China.
Molecules. 2019 Apr 30;24(9):1680. doi: 10.3390/molecules24091680.
Layered lithium-rich manganese oxide (LLO) cathode materials have attracted much attention for the development of high-performance lithium-ion batteries. However, they have suffered seriously from disadvantages, such as large irreversible capacity loss during the first cycle, discharge capacity decaying, and poor rate performance. Here, a novel method was developed to coat the surface of 0.4LiMnO∙0.6LiNiCoMnO cathode material with reduced graphene-oxide (rGO) in order to address these drawbacks, where a surfactant was used to facilitate the well-wrapping of rGO. As a result, the modified LLO (LLO@rGO) cathode exhibits superior electrochemical performance including cycling stability and rate capability compared to the pristine LLO cathode. In particular, the LLO@rGO with a 0.5% rGO content can deliver a high discharge capacity of 166.3 mAh g at a 5C rate. The novel strategy developed here can provide a vital approach to inhibit the undesired side reactions and structural deterioration of Li-rich cathode materials, and should be greatly useful for other cathode materials to improve their electrochemical performance.
层状富锂锰氧化物（LLO）阴极材料因其在高性能锂离子电池中的发展而备受关注。然而，它们存在严重的缺点，如在首次循环中不可逆容量损失大、放电容量衰减和倍率性能差。在这里，开发了一种新的方法，即用还原氧化石墨烯（rGO）对 0.4LiMnO·0.6LiNiCoMnO 阴极材料的表面进行包覆，以解决这些缺点，其中使用了表面活性剂以促进 rGO 的良好包裹。结果，改性的 LLO（LLO@rGO）阴极与原始的 LLO 阴极相比，表现出优异的电化学性能，包括循环稳定性和倍率性能。特别是，具有 0.5%rGO 含量的 LLO@rGO 可以在 5C 倍率下提供高达 166.3mAhg 的高放电容量。这里开发的新策略为抑制富锂阴极材料的不良副反应和结构恶化提供了一种重要方法，对于提高其他阴极材料的电化学性能应该非常有用。
