Sodium pre-intercalated carbon/V2O5 constructed by sustainable sodium lignosulfonate for stable cathodes in zinc ion batteries: A comprehensive study.

Aqueous zinc ion battery (AZIB) has been widely investigated in recent years because of its advantages of green, safe and abundant raw materials. It is necessary to continue to study how to prepare cathode materials with excellent performance and high cycling stability toward future commercialization. In this work, we proposed a strategy that uses sodium lignosulfonate as both carbon and sodium source to obtain a sodium pre-intercalated vanadium oxide/carbon (VO/LSC) composite as the cathode of AZIB. The carbon matrix could improve the electronic conductivity of vanadium oxide, while the sodium lignosulfonate can provide sodium ions pre-intercalated into the layered vanadium oxide simultaneously. Through this strategy, we obtained a vanadium-based cathode materials with high stability and excellent rate capability. The VO/LSC cathode delivered high capacities of 350 and 112.8 mAh g -1 at 0.1 and 4.0 A g -1 resepectively. We selected zinc sulfate and zinc trifluoromethyl sulfonate as electrolytes respectively, and analyzed the influence of electrolytes on the performance of VO/LSC. What's more, we used the oxygen in the environment to oxidize the low-priced vanadium oxide to achieve a self-charging AZIB. This paper provide a valuable strategy for the design of vanadium-base cathode material for AZIB, which can broaden the research and application of AZIB.