Urchin flower-like SnO2 nanosheets anchored on waste biomass carbon as advanced anode for lithium-ion batteries

Although SnO2 is considered a desirable anode for lithium-ion batteries benefitting from its high theoretical capacity, yet the low electrical conductivity and associated volume expansion substantially hinder the commercialization. Here, urchin flower-like SnO2 nanosheets were anchored on biomass porous carbon material converted from spent disposable bamboo chopsticks via a simple strategy. The prepared SnO2@carbon material could be regarded as a superior anode in lithium-ion batteries. The SnO2@carbon anode delivered an initial specific capacity of 1182.5 mAh g-1 under a current density of 0.1 A g-1 and maintained 275.8 mAh g-1 at 3 A g-1, suggesting the prominent rate capability. Notably, the SnO2@AC anode exhibited 570.5 mAh g-1 after 500 cycles at 0.5 A g-1. The remarkable performances are attributed to the nano-size of SnO2, which shortens the ion transport length and increases the active sites. Besides, the porous carbon material as anchoring substrate boosts the overall conductivity, promotes electrolyte penetration, and buffers volume expansion. Finally, a highly reversible conversion reaction between Li2O/Sn and SnO2, and mitigation of the agglomeration of SnO2 could be realized. The work can provide potential inspiration for waste resource recovery and development of metal oxide-based conversion-type materials for energy storage.