All-solid-state batteries (ASSBs), particularly those with Li-free anodes or even anode-free configurations, have attracted extensive attention due to high safety and energy density. However, chemical-mechanical degradation typically deteriorates the cycle life and energy of Li-free anode ASSBs with the absence of Li inventory.
Recently, Professor Shaohua Guo and Haoshen Zhou from Nanjing University enhanced the prelithiation agent Li5FeO4 (LFO) by coating it on Ni-rich layered oxide, which was then developed as a cathode material for all-solid-state batteries (ASSBs) with Li-free anodes. The coated LFO acts as an interfacial protective layer to prevent the highly oxidizing Ni-rich cathode from reacting with sulfide solid-state electrolytes (SSEs), mitigating the structural degradation of Ni-rich cathodes and the decomposition of SSE, resulting in excellent cycle life. Beneficial from the coated LFO in the cathode of the Li-free anode ASSBs, the reversible capacity improves from 174.7 mAh g−1 to 199.7 mAh g−1, and the capacity retention is enhanced from 33.8% to 84.8% after 100 cycles. Furthermore, the Li-free indium layer anode all-solid-state pouch cell equipped with the LFO-NCM cathode achieves a reversible capacity of 106.2 mAh and remains reversible (de)lithiation over 100 cycles. The Li-free silicon anode all-solid-state pouch cell equipped with the LFO-NCM cathode can obtain a discharge capacity of 1.1 Ah and a high energy density of up to 440 Wh kg−1 (based on the total mass of the composite cathode, Li-free silicon anode, and SSE film). Our work suggests that it is critical for ASSBs with Li-free anodes and sulfide-based SSEs to utilize both a prelithiation agent and a protective layer to obtain high energy density and stable cycle life.
Figure. Schematic of Li-free anode ASSBs equipped with bare NCM811 and LFO-coated NCM811 (LFO-NCM) cathodes during (de)lithiation.
The above result entitled Integrating Prelithiation and Interface Protection to Achieve High-Energy All-Solid-State Batteries is published on Angewandte Chemie International Edition. Prof. Shaohua Guo and Prof. Haoshen Zhou are the corresponding authors of the paper. Xiangqun Xu, and Shiyong Chu are the co-first authors. The authors thank the National Key R&D Program of China, the National Natural Science Foundation of China, the Natural Science Foundation of Jiangsu Province, etc for the funding support.
Article Link: https://doi.org/10.1002/anie.202415891
