Ji Hongxiang, Qiao Ronghan, Yu Hailong, Wang Shan, Liu Zhongzhu, Monteiro Robson, Ribas Rogerio, Zhu Yongming, Ben Liubin, Huang Xuejie
Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China.
ACS Appl Mater Interfaces. 2023 Aug 23;15(33):39291-39303. doi: 10.1021/acsami.3c06908. Epub 2023 Aug 14.
The particle morphology of LiNiO (LNO), the final product of Co-free high-Ni layered oxide cathode materials, must be engineered to prevent the degradation of electrochemical performance caused by the H2-H3 phase transition. Introducing a small amount of dopant oxides (NbO as an example) during the electrolysis synthesis of the Ni(OH) precursor facilitates the engineering of the primary particles of LNO, which is quick, simple, and inexpensive. In addition to the low concentration of Nb that entered the lattice structure, a combination of advanced characterizations indicates that the obtained LNO cathode material contains a high concentration of Nb in the primary particle boundaries in the form of lithium niobium oxide. This electrolysis method facilitated LNO (EMF-LNO) engineering successfully, reducing primary particle size and increasing particle packing density. Therefore, the EMF-LNO cathode material with engineered morphology exhibited increased mechanical strength and electrical contact, blocked electrolyte penetration during cycling, and reduced the H2-H3 phase transition effects.
无钴高镍层状氧化物正极材料的最终产物LiNiO（LNO）的颗粒形态必须经过设计，以防止由H2-H3相变引起的电化学性能退化。在Ni(OH)前驱体的电解合成过程中引入少量掺杂氧化物（以NbO为例）有助于对LNO的一次颗粒进行设计，这种方法快速、简单且成本低廉。除了进入晶格结构的低浓度Nb外，多种先进表征结果表明，所获得的LNO正极材料在一次颗粒边界处含有高浓度的以铌酸锂形式存在的Nb。这种电解方法成功地实现了LNO（EMF-LNO）的颗粒形态设计，减小了一次颗粒尺寸并提高了颗粒堆积密度。因此，具有设计形态的EMF-LNO正极材料表现出更高的机械强度和电接触性能，在循环过程中阻止了电解质渗透，并降低了H2-H3相变效应。
