Anode Interfacial Layer Construction via Hybrid Inhibitors for High-Performance Al-Air Batteries.

The self-corrosion of aluminum anodes is one of the key issues that hinder the development and application of low-cost and high-energy-density Al-air batteries (AABs). Herein, a hybrid corrosion inhibitor combining ZnO and acrylamide (AM) was developed to construct a dense protective interface on the Al anode to suppress the self-corrosion and enhance the electrochemical performance of AABs. Also, the results show that the hydrogen evolution rate with the optimal combination of hybrid inhibitors is 0.0848 mL cm-2 min-1, corresponding to the inhibition efficiency of 78.03%. The integrated AABs with hybrid inhibitors show remarkable capacities of 1240.6 mA h g-1 (25 mA cm-2) and 2444.1 mA h g-1 (100 mA cm-2) and a high power density of 63.7 mW cm-2. This shows that ZnO dissolves into the electrolyte and forms a loose and porous film on the Al surface. When AM is introduced into the ZnO-containing electrolyte, the adsorption of the amide group of AM on the surface of aluminum and ZnO occurs, which not only controls the growth morphology of ZnO but also enables ZnO to easily aggregate into a layer that is in close contact with the anode, efficiently suppressing self-corrosion. This work opens up the prospect of a corrosion inhibition mechanism for ZnO and AM in alkaline solutions and for developing effective organic/inorganic hybrid inhibitors.

A 3D-mixed ion/electron conducting scaffold prepared by in situ conversion for long-life lithium metal anodes.

Lithium (Li) metal is widely considered the most promising anode material because of its ultrahigh specific energy. However, the obvious volume change and uncontrollable dendrite growth hinder its commercial applications. Herein, we designed a 3D scaffold of Cu3P nanoarray-modified Cu foam via in situ conversion (3D MIECS). Uniform lithiophilic Cu3P nanoarrays were in situ grown inside the Cu foam (Cu3P NA@CF) that presented a high specific surface area and very low nucleation overpotential. Specifically, the lithiated Cu3P nanoarrays possess the features of mixed ion/electron conductivity and structural stability responsible for uniform Li deposition in the whole three-dimensional space of the metal skeleton, showing scarcely any volume expansion or structural collapse during the continuous Li plating/stripping process. Therefore, the modified Cu foam host achieves dendrite-free cycling over 600 cycles at a current density of 3 mA cm-2 with a coulombic efficiency (CE) of 99.1%. A 3D MIECS-Li||LiFePO4 full cell holds a capacity retention of 80% with a stable CE of 99.63% over 1000 cycles at 3 C.