Rich‐Carbonyl Carbon Catalysis Facilitating the Li <sub>2</sub> CO <sub>3</sub> Decomposition for Cathode Lithium Compensation Agent
Yingjie Wu, Jie Ju, Bolei Shen, Jie Wei, Hao Jiang, Chunzhong Li, Yanjie Hu
Abstract
Abstract The active lithium loss of lithium‐ion batteries can be well addressed by adding a cathode lithium compensation agent. Due to the poor conductivity and electrochemical activity, lithium carbonate (Li 2 CO 3 ) is not considered as a candidate. Herein, an effective cathode lithium compensation agent, the recrystallized Li 2 CO 3 combined with large specific surface area disordered porous carbon (R‐LCO@SPC) is prepared. The screened SPC makes it easier for nano‐sized Li 2 CO 3 to adsorb and decompose on carbon substrate, meantime, exposing plenty of catalytic active sites of C═O, which can significantly improve the electrochemical activity and conductivity of Li 2 CO 3 , thus greatly reducing the decomposition potential of Li 2 CO 3 (4.0 V) and releasing high irreversible capacity (580 mAh g −1 ) compared to the unmodified Li 2 CO 3 (nearly no capacity above 4.6 V). Meantime, the Li 2 CO 3 can disappear completely without any by‐product after the initial cycle accompanied by partially dissolved in electrolyte, optimizing the composition of SEI. The resultant lithium compensation agent applied to LMFP//graphite full cell exhibits a 19.1% increase in energy density, enhancing the rate and cycling performance, demonstrating great practical applications potential in high energy density lithium‐ion batteries.