Title: Lattice Engineering on Li2CO3-Based Sacrificial Cathode Pre-lithiation Agent for Improving The Energy Density of Li-Ion Battery Full-Cell

Authors: Yuanlong Zhu, Yilong Chen, Jianken Chen, Jianhua Yin, Zhefei Sun, Guifan Zeng, Xiaohong Wu, Leiyu Chen, Xiaoyu Yu, Haiyan Luo, Yawen Yan, Haitang Zhang, Baodan Zhang, Xiaoxiao Kuai, Yonglin Tang, Juping Xu, Wen Yin, Yongfu Qiu, Qiaobao Zhang, Yu Qiao*, Shi-Gang Sun

Abstract: Developing sacrificial cathode pre-lithiation technology to compensate for active lithium loss is vital for improving the energy density of lithium-ion battery full-cells. Li₂CO₃ owns high theoretical specific capacity, superior air stability, but poor conductivity as an insulator, acting as a promising but challenging pre-lithiation agent candidate. Herein, extracting a trace amount of Co from LiCoO₂ (LCO), we develop a lattice engineering through substituting Li sites with Co and inducing Li defects to obtain Co-Li₂CO₃@LCO, in which both the bandgap and Li-O bond strength have essentially declined. Benefiting from the synergistic effect of Li defects and bulk phase catalytic regulation of Co, the potential of Li₂CO₃ deep decomposition significantly decreases from typical >4.7 V to ∼4.25 V versus Li/Li⁺, presenting >600 mAh/g compensation capacity. Impressively, coupling 5 wt% Co-Li₂CO₃@LCO within NCM-811 cathode, 235 Wh/kg pouch-type full-cell is achieved, performing 88% capacity retention after 1000 cycles.

Full-Link: https://onlinelibrary.wiley.com/doi/10.1002/adma.202312159