Xiao Wei, Nie Yan, Miao Chang, Wang Jiale, Tan Yi, Wen Minyue
College of Chemistry and Environmental Engineering, Yangtze University, Jingzhou 434023, PR China.
College of Chemistry and Environmental Engineering, Yangtze University, Jingzhou 434023, PR China.
J Colloid Interface Sci. 2022 Feb;607(Pt 2):1071-1082. doi: 10.1016/j.jcis.2021.09.067. Epub 2021 Sep 15.
LiPO coating LiMgNiCoMnO (NCM83-MP) composite powders are successfully synthesized by first doping Mg into LiNiCoMnO by co-calcination processes and followed by HPO modifying the obtained LiMgNiCoMnO composite powders by sol-gel methods. Related physicochemical characterization results demonstrate that Mg doping can significantly enlarge the lattice space along the c-axis to 14.1431 Å and lower the Li/Ni mixing degree to 1.58 %, and HPO modifying can effectively reduce the residual lithium content and generate a homogeneous LiPO covering with a thickness of about 11.7 nm on the surface of the composite particles. Furthermore, the battery performance tests indicate that the coin cells assembled with NCM83-MP can exhibit excellent cycling performance, in which the distinguished discharge specific capacity of 157.4 mAh g at 2.0 C at 25 °C after 200 cycles and 154.6 mAh g at 2.0 C at 60 °C after 100cycles are amazingly retained, respectively. Additionally, the electrode can present a smaller gap of redox peaks of 0.10 V and a lower resistance value of 193.8 Ω compared to the ones of 0.49 V and 451.8 Ω of NCM83-0 after cycles. Those enhanced electrochemical properties are mainly ascribed to the synergetic effect of Mg doping and HPO modifying, which can not only stabilize the lattice structure but also provide fast transfer channels to facilitate Li ions migrating. Therefore, the proposed strategy may excavate new ideas to the further investigation of high-performance Ni-rich cathode materials for lithium ion battery.
通过共煅烧工艺首先将镁掺杂到LiNiCoMnO中，然后采用溶胶 - 凝胶法用HPO对所得LiMgNiCoMnO复合粉末进行改性，成功合成了LiPO包覆的LiMgNiCoMnO（NCM83 - MP）复合粉末。相关物理化学表征结果表明，镁掺杂可使沿c轴的晶格间距显著扩大至14.1431 Å，并将Li/Ni混合度降低至1.58%，而HPO改性可有效降低残余锂含量，并在复合颗粒表面生成厚度约为11.7 nm的均匀LiPO包覆层。此外，电池性能测试表明，用NCM83 - MP组装的扣式电池可表现出优异的循环性能，其中在25℃下2.0 C倍率下循环200次后，其出色的放电比容量为157.4 mAh/g，在60℃下2.0 C倍率下循环100次后，放电比容量为154.6 mAh/g，均令人惊讶地得以保持。此外，与循环后的NCM83 - 0相比，该电极的氧化还原峰间隙更小，为0.10 V，电阻值更低，为193.8 Ω。这些增强的电化学性能主要归因于镁掺杂和HPO改性的协同效应，这不仅可以稳定晶格结构，还能提供快速传输通道以促进锂离子迁移。因此，所提出的策略可能为锂离子电池高性能富镍正极材料的进一步研究挖掘新思路。
