A New Design Strategy Enables High Mn‐Utilization Rate in Aqueous Zinc–Manganese Batteries: Constructing Cathodic Local Mn‐Rich Region
Yonghang Liu, Yandong Ma, Yi Zhang, Yi Li, Juan Chen, Lei Wang, Shu‐Juan Bao, Yuruo Qi, Hao Chen, Maowen Xu
Abstract
Abstract The deposition–dissolution mechanism with a two‐electron transfer reaction endows aqueous Zn–Mn batteries with a desirable theoretical energy density. However, due to the limited solubility of traditional manganese‐based materials and the competitive Mn shuttle behavior, the practical performance is unsatisfactory. Herein, by synergistically incorporating a novel Mn‐rich Mn 4 N cathode with a plasma functionalized carbon nanotubes film (PCNT) interlayer, an aqueous Zn–Mn battery with a high Mn‐utilization rate and high energy/power density is successfully developed. Specifically, the Mn 4 N cathode boasts high manganese content and dissolution activity, thereby offering a copious supply of Mn 2+ ions for the battery system. The PCNT interlayer, with abundant micropore structures and functional groups, not only restrains the Mn 2+ shuttle by entrapping the dissolved Mn 2+ but also offers copious reaction sites, ensuring concentrating Mn 2+ on the cathodic side and maximizing their contribution to the electrochemical reaction. Consequently, Mn 4 N‐PCNT exhibits a low polarization voltage and superior Mn‐utilization rate (64.8%). Without the MnSO 4 additive, Mn 4 N‐PCNT achieves an ultra‐high energy density of 821.9 W h kg −1 and remarkable long‐term cycling stability (90% capacity retention over 9000 cycles). The delightful results demonstrate the practical application potential of Mn 4 N‐PCNT and open up new avenues for the rational design of advanced Zn–Mn batteries.