Bo Hu,Kang Han,Chunhua Han,Lishan Geng,Ming Li,Ping Hu,Xuanpeng Wang
Aluminum-ion batteries have attracted great interest in the grid-scale energy storage field due to their good safety, low cost and the high abundance of Al. However, Al anodes suffer from severe dendrite growth, especially at high deposition rates. Here, we report a simple strategy for constructing a highly reversible, dendrite-free, Al-based anode through directly introducing a solid-solution-based metal coating to a Zn foil substrate. Compared with Cu foil substrates and bare Al, a Zn foil substrate shows a lower nucleation barrier of Al deposition due to the intrinsic, definite solubility between Al and Zn. During Al deposition, a thin, solid-solution alloy phase is first formed on the surface of the Zn foil substrate and then guides the parallel growth of flake-like Al on Zn substrate. The well-designed, Zn-coated Al (Zn@Al) anode can effectively inhibit dendrite growth and alleviate the corrosion of the Al anode. The fabricated Zn@Al–graphite battery exhibits a high specific capacity of 80 mAh·g−1and an ultra-long lifespan over 10,000 cycles at a high current density of 20 A·g−1in low-cost molten salt electrolyte. This work opens a new avenue for the development of stable Al anodes and can provide insights for other metal anode protection.Keywords:aluminum-ion battery;metal coating;solid-solution alloy;dendrite-free anode
Among the alloying-type anodes, elemental Sb possesses the suitable yet safe plateau, simple lithiation pathway, small voltage polarization, high conductivity, and superior cycle stability. However, challenge is that its intrinsic capacity is rather low (660 mAh g −1 ), <1/6 of silicon. Herein, we propose a seamless integration strategy by merging the voltage and capacity of phosphorus and antimony into a solid solution alloy. Interestingly, the enlistment of P is found greatly enlarge the capacity from 660 to 993 mAh g −1 for such Sb 30 P 30 solid solution, while maintaining a single and stable discharge plateau (~0.79 V) similar to elemental Sb. Various experimental characterizations including XPS, PDF, Raman, and EDS mapping reveal that in such a material the P and Sb atoms have interacted with each other to form a homogenous solid solution alloy, rather than a simple mixing of the two substances. Thus, the Sb 30 P 30 exhibits superior rate performances (807 mAh g −1 at 5000 mA g −1 ) and cyclability (821 mAh g −1 remained after 300 cycles). Furthermore, such Sb 60-x P x alloys can even deliver 621 mAh g −1 at −30°C, which can be served as the alternative anode materials for high-energy and low-temperature batteries. This unique seamless integration strategy based on solid solution chemistry can be easily leveraged to manipulate the capacity of other electrode materials at similar voltage.