Promoting Proton Migration Kinetics by Ni²⁺ Regulating Enables Improved Aqueous Zn‐MnO₂ Batteries

Abstract

The energy storage behaviors of MnO2 for aqueous Zn‐MnO2 batteries mainly depend on the Zn2+/H+ intercalation but are limited by poor ion/electron migration dynamics and stability. Herein, a strategy is proposed that promoting proton migration kinetics ameliorates H+ storage activity by introducing Ni2+ into γ‐MnO2 (Ni‐MnO2). Ni2+ can lower the diffusion barrier of H+ and selectively induce the ion intercalation, thereby alleviating the electrostatic interaction with the lattice. Moreover, Ni2+ enables the adjacent [MnO6] octahedrons to have better electron conductivity. The Ni‐MnO2 exhibits superior rate performance (nearly four times specific capacity compared with MnO2) and ultra‐long‐cycle stability (100% of capacity retention after 11 000 cycles at 3.0 A g−1). The calculation indicates that the Ni‐MnO2 allows H+ migrate rapidly along the one‐dimensional tunnel due to reduction of the activation energy caused by Ni2+ regulating, thus achieving excellent reaction kinetics. This work brings great potential for the development of high‐performance aqueous Zn‐MnO2 batteries.

Suppressed Dissolution and Enhanced Desolvation in Core–Shell MoO3@TiO2 Nanorods as a High‐Rate and Long‐Life Anode Material for Proton Batteries

“…The b values of 0.98/0.99 (P 3 /P 3 ′) suggest that the reaction between −0.45 and −0.3 V is surface controlled. [47] In this context, the superior reaction kinetics likely comes from fast desolvation and good electron/ion conductivity. R ct at different temperatures are used to calculate the apparent activation energy (E a ) for the desolvation process on the electrode/electrolyte interface (Figure S14, Supporting Information).…”

Ni‐MnO2/Graphene as Cathode Material for Super‐Capacity Aqueous Rechargeable Zn‐Ion Battery

“…It is worth mentioning that the specific capacity and rate capability of NMO/rGO are comparable to or better than many other reported cathode materials. [ 10–13,18,33,34 ]…”

“…[7][8][9][10] Ji et al reported that Ni-γ-MnO 2 exhibited excellent rate performance and ultralong cycling stability (100% capacity retention after 11 000 cycles at 3.0 A g À1 ), because Ni 2þ doping can reduce the diffusion barrier of H þ , alleviate the electrostatic interaction with the lattice, and improve the electronic conductivity of materials. [11] Zhang et al reported that Ni-doped Mn 2 O 3 (NM) showed a high specific capacity of 252 mAh g À1 (0.1 A g À1 ), which is three times higher than that of pure Mn 2 O 3 (72 mAh g À1 ). It is found that Ni 2þ doping can improve electrical conductivity, the reaction kinetics, and the electrochemical properties of NM.…”

Bulk-phase and interface stability strategies of manganese oxide cathodes for aqueous Zn-MnOx batteries

“…By changing the electronic state structure of t 2 g 3 egfn1 with high spin of Mn 3+ and substituting transition metal elements for Mn 3+ , the structural stability of MnO x cathode material is improved to suppress the J-T effect, so as to improve its cycle stability, which has been deeply studied in the application of lithium/sodium ion batteries (Li et al, 2009;Xiao et al, 2018). Defect engineering (such as vacancy and doping) can improve the structural stability of MnO x , inhibit Mn 3+ disproportionation caused by J-T effect, and improve the cycle stability of MnO x zinc storage process (H Zheng et al, 2022;Ji et al, 2022). At present, part of the work has carried out defect engineering research on manganese-based cathode materials for aqueous zinc ion batteries.…”