Acta Chimica Sinica ›› 2024, Vol. 82 ›› Issue (11): 1134-1141.DOI: 10.6023/A24080241 Previous Articles     Next Articles

Article

梯度多孔结构设计提升高镍层状氧化物正极材料高压循环稳定性

王舒玮a,b,c, 张建勋a, 成业d, 章立寒e,*(), 田华军a,*(), 李宝华b,c,*()   

  1. a 华北电力大学电站能量传递转化与系统教育部重点实验室 北京 102206
    b 清华大学深圳国际研究生院 深圳 518055
    c 深圳市下一代动力与储能电池关键技术工程研究中心 深圳 518055
    d 矿冶科技集团有限公司 北京 100160
    e 北京工业大学材料科学与工程学院 北京 100124
  • 投稿日期:2024-08-17 发布日期:2024-10-10
  • 基金资助:
    国家自然科学基金(52302249); 国家自然科学基金(12304003); 国家自然科学基金(52072208); 国家自然科学基金(52261160384); 国家自然科学基金(22379085); 国家自然科学基金(52302278)

Gradient-porous-structured Ni-rich Layered Oxide Cathodes Improve the High Voltage Cycling Stability

Shuwei Wanga,b,c, Jianxun Zhanga, Ye Chengd, Lihan Zhange(), Huajun Tiana(), Baohua Lib,c()   

  1. a Key Laboratory of Power Station Energy Transfer Conversion and Systems Ministry of Education, North China Electric Power University, Beijing 102206, China
    b Tsinghua Shenzhen International Graduate School, Shenzhen 518055, China
    c Shenzhen Engineering Research Center on Key Technology of Next-Generation Power and Energy-Storage Battery, Shenzhen 518055, China
    d BGRIMM Technology Group, Beijing 100160, China
    e College of Materials Science & Engineering, Beijing University of Technology, Beijing 100124, China
  • Received:2024-08-17 Published:2024-10-10
  • Contact: *E-mail: zhanglh06@bjut.edu.cn; Huajun.Tian@ncepu.edu.cn; libh@sz.tsinghua.edu.cn
  • Supported by:
    National Natural Science Foundation of China(52302249); National Natural Science Foundation of China(12304003); National Natural Science Foundation of China(52072208); National Natural Science Foundation of China(52261160384); National Natural Science Foundation of China(22379085); National Natural Science Foundation of China(52302278)

Nickel-rich layered oxides (LiNixCoyMn1-x-yO2, x≥0.8, NCM) are the most promising cathode material for next-generation high-energy batteries owing to their low production cost, high specific capacity and high operating voltage. However, the practical deployment of high-voltage NCM cathodes is still plagued by mechanical failure of NCM secondary particles due to the internal strain accumulation and particle crack during (de)lithiation. Herein, we report a convenient coprecipitation strategy to introduce gradient porous structure into the polycrystalline NCM secondary particles. Through multistage micro- and nanostructural tailoring from hydroxide precursor in coprecipitation process to the lithiated oxide during the lithiation stage, which refers to optimal engineering of the precursor micro- and nano-structure by introducing extra organic polymer (polystyrene-acrylonitrile copolymer) as heterogeneous nucleation seeds and alkyl diphenyl ether disulfonate disodium as dispersants, we optimize the primary particle morphology containing nano-voids and secondary particle containing gradient porous structure of the cathode. Through high-resolution aberration-corrected scanning transmission electron microscopy and scanning electron microscopy, the detailed gradient porous structure of the as-obtained nickel-rich layered oxide cathode is clarified, and the formation of gradient porous structure is attributed to the rapid diffusion of the carbonized organic matter by the calcination treatment under oxygen atmosphere during the lithiation stage. This gradient-porous- structured nickel-rich layered oxide cathode can mitigate the anisotropic volume change of the primary particles, suppress intergranular/intragranular cracks and limit impedance growth effectively. The as-obtained cathode exhibits high specific capacity of 180.1 mAh•g−1 (1 C, 25 ℃) and capacity retention of 87.6% after 300 cycles even charged to a high cut-off voltage of 4.5 V. Moreover, this cathode presents enhanced high reversible capacity and cycling stability in a wide temperature range of -20~60 ℃. This study suggests the gradient porous structure design can homogenize stress distribution and mitigate volumetric change, representing a promising pathway to tackle the structural instability upon high-voltage cycling.

Key words: nickel-rich layered oxides, high voltage, mechanical failure, gradient porous structure, wide temperature range