Carbon armor-layer decorated Li3V2(PO4)3 core-shell cathode materials derived from nitrogen doped lignin waste liquor for robust lithium ion batteries

Simultaneous boosting the lithium ions extraction/insertion kinetics and improving the structural stability of Li3V2(PO4)3 (LVP) cathode material highly determine the capacity and lifespan of lithium-ion batteries (LIBs). Herein, terminal oxygen-containing functional groups enriched carbonaceous layer from N doped lignin waste liquor is successfully demonstrated as the armor layer to decorate LVP with core-shell structures for robust LIBs. To the best of our knowledge, it is the first exploration using N doped lignin waste liquor as carbon source in synthesizing high-performance LVP cathode materials. More importantly, owing to the facilitated reversible V3+/ V4+ redox couple induced by oxygen-containing functional groups aligning with the promoted Li+ kinetic behaviors, the champion device delivered a high initial discharge capacity of 126.9 mA h g+1 (~95% of the theoretical capacity) at 0.5C. Furthermore, the optimized battery displays superior capacity retention of 88.9% after 1000 cycles at a high rate of 10C because of the suppressed crystallization expand and transition metal dissolution.

Automated summary

In this study, a carbonaceous layer rich in oxygen-containing functional groups was successfully synthesized from N-doped lignin waste liquor and used as an armor layer to decorate the LVP cathode material, thereby improving the capacity and lifespan of lithium-ion batteries. The champion device exhibited a high initial discharge capacity and excellent capacity retention at high rates.