Seong Won Mo, Cho Kwang-Hwan, Park Ji-Won, Park Hyeokjun, Eum Donggun, Lee Myeong Hwan, Kim Il-Seok Stephen, Lim Jongwoo, Kang Kisuk
Department of Materials Science and Engineering, Research Institute of Advanced Materials (RIAM), Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, Republic of Korea.
Current address: Materials Science and Engineering Program and Texas Materials Institute, The University of Texas at Austin, Austin, TX, 78712, USA.
Angew Chem Int Ed Engl. 2020 Oct 12;59(42):18662-18669. doi: 10.1002/anie.202007436. Epub 2020 Aug 31.
The rampant generation of lithium hydroxide and carbonate impurities, commonly known as residual lithium, is a practical obstacle to the mass-scale synthesis and handling of high-nickel (>90 %) layered oxides and their use as high-energy-density cathodes for lithium-ion batteries. Herein, we suggest a simple in situ method to control the residual lithium chemistry of a high-nickel lithium layered oxide, Li(Ni Co Mn )O (NCM9163), with minimal side effects. Based on thermodynamic considerations of the preferred reactions, we systematically designed a synthesis process that preemptively converts residual Li O (the origin of LiOH and Li CO ) into a more stable compound by injecting reactive SO gas. The preformed lithium sulfate thin film significantly suppresses the generation of LiOH and Li CO during both synthesis and storage, thereby mitigating slurry gelation and gas evolution and improving the cycle stability.
氢氧化锂和碳酸锂杂质（通常称为残余锂）的大量生成，是大规模合成和处理高镍（>90%）层状氧化物以及将其用作锂离子电池高能量密度阴极的实际障碍。在此，我们提出一种简单的原位方法，以控制高镍锂层状氧化物Li(NiCoMn)O（NCM9163）的残余锂化学性质，且副作用最小。基于对优先反应的热力学考虑，我们系统地设计了一种合成工艺，通过注入反应性SO气体，将残余的LiO（LiOH和LiCO的来源）预先转化为更稳定的化合物。预先形成的硫酸锂薄膜在合成和储存过程中均能显著抑制LiOH和LiCO的生成，从而减轻浆料凝胶化和气体逸出，并提高循环稳定性。
