Search

Owing to their high volumetric capacity, reasonably low redox potential, and budget friendliness, manganese metal batteries (MnMBs) are excellent candidates for batteries with a high energy-to-price ratio. However, since there is no suitable electrolyte ensuring reversible Mn plating/stripping due to the low redox potential of the Mn2+/Mn redox couple and the strong interaction between charge-dense Mn2+ions and solvents, the development of MnMBs has been largely constrained. Herein, a halogen-mediated non-aqueous electrolyte (HM-NAE) is developed to enable highly reversible Mn plating/stripping. Benefiting from this halogen-mediated mechanism, the asymmetric Mn cell can cycle stably more than 1,000 h with a Coulombic efficiency close to 100%. Moreover, a Mn|HM-NAE|Mo6S8full cell with high electrochemical performances is constructed and fully understood. This work offers a new avenue to the development of rechargeable, non-aqueous MnMB through electrolyte engineering, which can also shed light on other multivalent metal batteries and electroplating industry.

An aqueous electrolytic MnO2–Zn battery with eye-catching Mn2+/MnO2cathode chemistry has been attracting immense interest for next-generation energy storage devices due to its irreplaceable advantages. However, the limited MnO2conductivity restricts its long service life at high areal capacities. Here, we report a high-performance electrolytic MnO2–Zn battery via a bromine redox mediator, to enhance its electrochemical performance. The MnO2/Br2–Zn battery displays a high discharge voltage of 1.98 V with a capacity of ∼5.8 mAh cm–2. It also shows an excellent rate performance of 20 C with a long-term stability of over 600 cycles. Furthermore, the scaled-up MnO2/Br2–Zn battery with a capacity of ∼950 mAh exhibits a stable 100 cycles with a practical cell energy density of ∼32.4 Wh kg–1and an attractively low energy cost of below 15 US$ kWh–1. The design approach can be generalized to other electrodes and battery systems, thus opening up new possibilities for large-scale energy storage.

Aqueous zinc (Zn) batteries have attracted significant attention for large-scale energy storage applications due to their advantages of high theoretical capacity, high-safety and low-cost. However, the commercialization of Zn batteries is hindered by the low utilization and parasitic reactions of the Zn anode. Herein, we design a three-dimensional nano-copper host modified by zincophilic antimony (Sb) nanoparticles (referred to as ZA@3D-nanoCu) for dendrite-free and anode-free Zn batteries. The ZA@3D-nanoCu offers adequate zincophilic sites with homogeneous Zn nucleation and uniform current density distribution for Zn plating/stripping. It is further revealed that the synergistic effect of 3D structures and zincophilic particles can induce uniform zinc deposition for highly reversible plating/stripping. The dendrite-free Zn plating/stripping on the 3D-nanoCu substrate can stably cycle for over 1100 h at an areal capacity of 2 mAh cm-2with nearly 100% Zn utilization, much superior to the planar Cu foil without any structural design. By coupling the ZA@3D-nanoCu anode with a bromine cathode, the anode-free Zn-Br2battery can be cycled stably over 1000 cycles at a high areal capacity of 10 mAh cm-2. The anode-free ZA@3D-nanoCu host with remarkable advantages for stable Zn plating/stripping offers a new arena for large-scale energy storage applications of Zn batteries.