Rechargeable aqueous Zn/MnO battery chemistry in a neutral or mildly acidic electrolyte has attracted extensive attention recently because all the components (anode, cathode, and electrolyte) in a Zn/MnO battery are safe, abundant, and sustainable. However, the reaction mechanism of the MnO cathode remains a topic of discussion. Herein, we design a highly reversible aqueous Zn/MnO battery where the binder-free MnO cathode was fabricated by in situ electrodeposition of MnO on carbon fiber paper in mild acidic ZnSO+MnSO electrolyte. Electrochemical and structural analysis identify that the MnO cathode experience a consequent H and Zn insertion/extraction process with high reversibility and cycling stability. To our best knowledge, it is the first report on rechargeable aqueous batteries with a consequent ion-insertion reaction mechanism.

We report the discovery of a dramatically enhanced N electroreduction reaction (NRR) selectivity under ambient conditions via the Li incorporation into poly(N-ethyl-benzene-1,2,4,5-tetracarboxylic diimide) (PEBCD) as a catalyst. The detailed electrochemical evaluation and density functional theory calculations showed that Li association with the O atoms in the PEBCD matrix can retard the HER process and can facilitate the adsorption of N to afford a high potential scope for the NRR process to proceed in the "[O-Li]·N-H" alternating hydrogenation mode. This atomic-scale incorporation strategy provides new insight into the rational design of NRR catalysts with higher selectivity.

The amount of spent lithium-ion batteries has grown dramatically in recent years, and the development of a recycling process for spent lithium-ion batteries is necessary and urgent from the viewpoints of environmental protection and resource savings. The hydrometallurgical process is considered to be the most suitable method for the recycling of spent lithium-ion batteries. The current status of hydrometallurgical recycling technologies of spent lithium-ion batteries is reviewed in this paper. A series of hydrometallurgical procedures including pretreatment of the spent lithium-ion batteries, leaching process and separation of valuable metals from leaching solution are introduced in detail, and their advantages and problems are analyzed. Finally, the prospects and direction of the recycling of spent lithium-ion batteries are put forward. It is pointed out that a more flexible and universal process is required for the recovery of different types of spent lithium-ion batteries. Besides cathode active materials, the other components of spent lithium-ion batteries including electrolyte and anode materials also need to be recovered due to their potential environmental hazards.

In the current research project, we have prepared a novel Sb@C nanosphere anode with biomimetic yolk-shell structure for Li/Na-ion batteries via a nanoconfined galvanic replacement route. The yolk-shell microstructure consists of Sb hollow yolk completely protected by a well-conductive carbon thin shell. The substantial void space in the these hollow Sb@C yolk-shell particles allows for the full volume expansion of inner Sb while maintaining the framework of the Sb@C anode and developing a stable SEI film on the outside carbon shell. As for Li-ion battery anode, they displayed a large specific capacity (634 mAh g), high rate capability (specific capabilities of 622, 557, 496, 439, and 384 mAh g at 100, 200, 500, 1000, and 2000 mA g, respectively) and stable cycling performance (a specific capacity of 405 mAh g after long 300 cycles at 1000 mA g). As for Na-ion storage, these yolk-shell Sb@C particles also maintained a reversible capacity of approximate 280 mAh g at 1000 mA g after 200 cycles.

Suppressing the Sn coarsening in the Li2O matrix enabled highly reversible conversion between Li2O and SnO2 and an initial Coulombic efficiency of ∼95.5% was achieved.