Enhancement of the interfacial reaction on mesoporous RuO₂ for next generation Li batteries

In order to develop high energy density Li rechargeable batteries, nano-sized materials have attracted attention as the active materials. Mesoporous materials consist of the micrometre-sized particles, and they have high surface area due to their mesopore and thin wall thickness of framework. Here, we synthesize a highly ordered mesoporous RuO₂ to investigate the effect that the mesoscopic structure has on the capacity and their corresponding reaction mechanism of Li rechargeable battery. The synthesized mesoporous RuO₂ shows an initial discharge capacity of 1366 mAh g⁻¹ on mesoporous RuO₂, which is higher than that of commercial RuO₂. Our findings via In situ X-ray analysis techniques combined with electrochemical analysis demonstrate that the additional capacity of mesoporous RuO₂ is resulted from the enhanced interfacial reaction between Ru metal and Li₂O formed by conversion reaction of RuO₂. Nano-size effects of mesoporous structure such as high surface area, easy electron transport, and small domain would enable to improve the interfacial reaction of highly ordered mesoporous RuO₂. The understanding of this relationship between structural engineering and electrochemical properties provides the insight into development of high energy density anode materials in next generation Li rechargeable battery.