Metal sulfides encapsulated in doped carbon aerogel towards superior and safe energy storage: Two birds with one stone

Abstract

Up to now, lithium/sodium ion batteries (LIBs/SIBs) are deemed as the ideal candidates for traditional fossil energy. However, the absence of suitable Li+/Na+ reservoirs and the hazard of thermal runway have plagued their usages. Using Li4Ti5O12 or TiO2 anode promotes the thermal safety of LIBs/SIBs but reduce their electrochemical property. How to achieve the balanced performances has been an urgency. Here, we have delicately designed a 3D micro-nanostructure of CoS2/doped carbon aerogel (CoS2@NCA), via “killing two birds with one stone” strategy. When used as LIBs anode, CoS2@NCA delivers a high capacity of 639.5 mAh g−1 after operating at 1 A g−1 for 250 cycles, giving a low-capacity attenuation rate of 0.048 % per cycle. Meanwhile, the reduced maximum temperature and maximum heating rate of thermal runaway (TR) are observed for cell. When used as SIBs anode, CoS2@NCA delivers a high capacity of 620.9 mAh g−1 at 100th cycle as working at 1 A g−1. Likewise, the activation energy for TR is promoted. Overall, the utilization of CoS2@NCA enables the superior and safe energy storage.