Scalable spray-dried high-capacity MoC1-x/NC-Li2C2O4 prelithiation composite for lithium-ion batteries

Li2C2O4 is recognized as a promising prelithiation reagent for compensating active lithium owing to its residue-free, high-capacity, air-stable and cost-effective advantages. However, the inherent challenges of low conductivity and high reaction energy barriers necessitate the incorporation of a catalyst to expedite charge conduction and enhance electrochemical activity. It is essential to achieve an efficient composite Li2C2O4 with the catalyst while maintaining substantial prelithiation capacity. Herein, a scalable spray-dried strategy is developed to fabricate MoC1-x/NC-Li2C2O4 composites. The defect-rich nano-MoC1-x/NC catalysis facilitates intimate contact with Li2C2O4, leading to the formation of homogeneous microspheres that promote efficient solid-solid catalysis. Remarkably, the specific capacity of MoC1-x/NC-Li2C2O4 can reach up to 1117 mAh g−1 (calculation based on the complete release of CO2) with a low ratio of catalysts, demonstrating significant application potential. Furthermore, the activation potential of homogeneous MoC1-x/NC-Li2C2O4 composite can be reduced to 4.12 V at 50°C, while maintaining favorable electrode integrity and wettability. Upon implementation in Gr||NCM622 and SiC||NCM622 full cell, the initial discharge specific capacity is improved by 10.5% and 11.6%, respectively. Notably, sufficient active lithium post-prelithiation preserves the cathode and SEI structural stability, ensuring a stable cycling performance. This work presents a scalable prelithiation material with great promise for advanced lithium-ion battery applications.