| Abstrakt: |
Aqueous dual-ion batteries have good safety, environmental compatibility, and low cost due to the use of an aqueous electrolyte. However, water electrolysis occurs during charging at high potential, resulting in a poor cyclic stability of aqueous dual-ion batteries. Hence, novel anode materials are urgently needed to be developed for aqueous dual-ion batteries with low water electrolysis. A niobium-based binaryphase composite material is reported with a capacity of 135 mA h g-1 at a current density of 0.2 mA cm-2 and with excellent reversibility in the potential range of -1.3-0 V vs. Ag/AgCl. The activation energy of Li+ intercalation was obviously decreased because of the formation of an interface, which enhanced the Li+ intercalation reaction between FeNbO4 and MoNb12O33. In addition, the lower amount of Fe2+ in the lattice of MoNb12O33 caused localized compressive strain, which promoted fast Li+ diffusion in MoNb12O33. A full dual-ion battery of 3.0 V was constructed using the binary-phase niobium-based composite for the anode, and demonstrated a high cycle stability and an average coulombic efficiency of 91% over 300 cycles. Furthermore, considering both the electrolyte and electrode materials, the theoretical energy density of this dual-ion battery was estimated to be 250 W h kg-1, which is close to that of the current Li-ion rechargeable battery. [ABSTRACT FROM AUTHOR] |
