A Scalable Cathode Chemical Prelithiation Strategy for Advanced Silicon-Based Lithium Ion Full Batteries

A silicon anode with ultra-high specific capacity has motivated tremendous exploration for high-energy-density lithium ion batteries while it still faces serious issues of irreversible lithium loss, unstable electrode electrolyte interface (SEI), and huge volume expansion. Prelithiation is a crucial technology to alleviate the harm of active lithium loss of silicon-based full-cell systems. Herein, we reported a cathode prelithiation method using Li2S-PAN as a lithium donor, which was synthesized via chemical reaction between sulfurized polyacrylonitrile and Li-biphenyl complex. The Li2S-PAN with an initial charging capacity of 668 mAh g(-1) (2.5-4.0 V) is loaded on the LiFePO4 electrode, and the LiFePO4/Li2S-PAN composite electrode displays a high initial charge capacity of 206 mAh g(-1), which is 22.3% higher than the pristine LiFePO4. With a silicon/graphite/carbon (Si/G/C) composite anode, the Si/G/C parallel to LiFePO4/Li2S-PAN full cell exhibits a reversible capacity of 123 and 107 mAh g(-1) in the 1st and 10th cycle, which is 15.5 and 24.5% higher than the Si/G/C parallel to iFePO(4) battery, respectively. The SEI layer of the silicon anode in the Si/G/C parallel to LiFePO4/Li2S-PAN cell contains abundant conductive LiF species, which can enhance the interfacial stability and reaction kinetics of the cells. The proposed cathode prelithiation process is compatible with the industrial roll-to-roll electrode preparation process, exhibiting a promising application prospect.

Automated summary

This study presents a cathode prelithiation method using Li2S-PAN as a lithium donor, which enhances the initial charge capacity of LiFePO4 electrodes and improves the performance of full-cell systems. The combination with a silicon anode results in higher reversible capacity, enhanced interfacial stability, and improved reaction kinetics in the cells. The proposed cathode prelithiation process shows compatibility with industrial electrode preparation processes, showing promising application prospects.