Stable Interface between a NaCl-AlCl3 Melt and a Liquid Ga Negative Electrode for a Long-Life Stationary Al-Ion Energy Storage Battery

An artificial aluminum-tin alloy layer on aluminum metal anodes for ultra-stable rechargeable aluminum-ion batteries

Rechargeable aluminum ion batteries (RAIBs) exhibit great potential for next-generation energy storage systems owing to the abundant resources, high theoretical volumetric capacity and light weight of the Al metal anode. However, the development of RAIBs based on Al metal anodes faces challenges such as dendrite formation, self-corrosion, and volume expansion at the anode/electrolyte interface, which needs the rational design of an aluminum anode for high-performance RAIBs. This work proposes a novel and low-cost strategy by utilizing an alloy electrodeposition method in a low-temperature molten salt system to fabricate an aluminum-tin (AlSn) alloy coating layer on copper foil as the anode for RAIBs, which successfully addresses the issues of dendrite formation and corrosion at the anode/electrolyte interface. The artificial AlSn alloy layer could enhance the active sites for metal Al homogeneous deposition and effectively retard the dendrite formation, which was verified by an in situ optical microscopy study. The symmetric AlSn@Cu cell demonstrates a low average overpotential of ∼38 mV at a current density of 0.5 mA cm-2 and a long-term lifespan of over 1100 h. Moreover, the AlSn@Cu//Mo6S8 full cells deliver a high capacity of 114.9 mA h g-1 at a current density of 100 mA g-1 and maintain ultra-stable cycling stability even over 1400 cycles with a ∼100% coulombic efficiency (CE) during the long-term charge/discharge processes. This facile alloy electrodeposition approach for designing high-performance Al-based anodes provides insights into the understanding of artificial interface chemistry on Al-based anodes and potentially accelerates the design of high-performance RAIBs.

Nonaqueous Rechargeable Aluminum Batteries: Progresses, Challenges, and Perspectives

For significantly increasing the energy densities to satisfy the growing demands, new battery materials and electrochemical chemistry beyond conventional rocking-chair based Li-ion batteries should be developed urgently. Rechargeable aluminum batteries (RABs) with the features of low cost, high safety, easy fabrication, environmental friendliness, and long cycling life have gained increasing attention. Although there are pronounced advantages of utilizing earth-abundant Al metals as negative electrodes for high energy density, such RAB technologies are still in the preliminary stage and considerable efforts will be made to further promote the fundamental and practical issues. For providing a full scope in this review, we summarize the development history of Al batteries and analyze the thermodynamics and electrode kinetics of nonaqueous RABs. The progresses on the cutting-edge of the nonaqueous RABs as well as the advanced characterizations and simulation technologies for understanding the mechanism are discussed. Furthermore, major challenges of the critical battery components and the corresponding feasible strategies toward addressing these issues are proposed, aiming to guide for promoting electrochemical performance (high voltage, high capacity, large rate capability, and long cycling life) and safety of RABs. Finally, the perspectives for the possible future efforts in this field are analyzed to thrust the progresses of the state-of-the-art RABs, with expectation of bridging the gap between laboratory exploration and practical applications.