Ding Xiaokai, Luo Dong, Cui Jiaxiang, Xie Huixian, Ren Qingqing, Lin Zhan
Guangzhou Key Laboratory of Clean Transportation Energy Chemistry, School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou, 510006, China.
Angew Chem Int Ed Engl. 2020 May 11;59(20):7778-7782. doi: 10.1002/anie.202000628. Epub 2020 Mar 3.
Voltage decay and capacity fading are the main challenges for the commercialization of Li-rich Mn-based layered oxides (LLOs). Now, a three-in-one surface treatment is designed via the pyrolysis of urea to improve the voltage and capacity stability of Li Mn Ni O (LMNO), by which oxygen vacancies, spinel phase integration, and N-doped carbon nanolayers are synchronously built on the surface of LMNO microspheres. Oxygen vacancies and spinel phase integration suppress irreversible O release and help lithium ion diffusion, while N-doped carbon nanolayer mitigates the corrosion of electrolyte with excellent conductivity. The electrochemical performance of LMNO after the treatment improves significantly; the capacity retention rate after 500 cycles at 1 C is still as high as 89.9 % with a very small voltage fading rate of 1.09 mV cycle . This three-in-one surface treatment strategy can suppress the voltage decay and capacity fading of LLOs.
电压衰减和容量衰减是富锂锰基层状氧化物（LLOs）商业化面临的主要挑战。现在，通过尿素热解设计了一种三合一表面处理方法，以提高LiMnNiO（LMNO）的电压和容量稳定性，通过该方法在LMNO微球表面同步构建氧空位、尖晶石相整合和氮掺杂碳纳米层。氧空位和尖晶石相整合抑制了不可逆的氧释放并有助于锂离子扩散，而氮掺杂碳纳米层以优异的导电性减轻了电解质的腐蚀。处理后的LMNO的电化学性能显著提高；在1C下500次循环后的容量保持率仍高达89.9%，电压衰减率非常小，为1.09mV/循环。这种三合一表面处理策略可以抑制LLOs的电压衰减和容量衰减。
