Boosted Charge Transfer in Twinborn α-(Mn₂O₃–MnO₂) Heterostructures: Toward High-Rate and Ultralong-Life Zinc-Ion Batteries

Abstract

Aqueous ZIBs are one of the most promising nextgeneration rechargeable batteries because of the high capacity, high hydrogen evolution overpotential, and chemically stable reversible plating/stripping of the zinc electrode in the mild aqueous electrolyte. However, there are limited cathode materials that can store Zn 2+ reversibly with superior cycling and rate capability. Herein, hierarchically porous nanorods composed of twinborn α-(Mn 2 O 3 −MnO 2 ) heterostructures are proposed as a robust cathode for Zn storage. Thanks to the hierarchically porous nanorod morphology and the abundant interface of the heterostructures involving a built-in electric field, the as-obtained twinborn α-(Mn 2 O 3 −MnO 2 ) electrode delivers a high capacity of 170 mA h g −1 for 2000 cycles at 500 mA g −1 and shows an excellent rate capability of up to 1.5 A g −1 with a capacity of 124 mA h g −1 . The inspiring results achieved exhibit the enormous potential of the highperformance heterostructure cathode for fast and stable ZIBs.

Bi3+ Induced Crystal Growth of a Symbiotic Heterojunction Enables Long‐Lifespan Zn‐Ion Batteries

“…It can be seen that elemental Bi, Mn, and O signals are detected in HIP‐Bi‐600 and HIP‐Bi‐500, while only Mn and O elements exist in HIP‐0‐600 and HIP‐0‐500. In the high‐resolution Mn 2p spectra of HIP‐Bi‐600, three sets of spin‐orbit‐resolved peaks can be resolved as Mn 4+ (2 p 1/2 , 654.8 eV; 2 p 3/2 , 643.5 eV); Mn 3+ (2 p 1/2 , 653.8 eV; 2 p 3/2 , 642.3 eV) and Mn 2+ (2 p 1/2, 652.6 eV; 2 p 3/2 , 640.9 eV), indicating the existence of the manganese mixed phase, which is consistent with literature [25] . Similarly, HIP‐0‐600 and HIP‐0‐500 electrodes also display three pairs of peaks.…”

“…synthesized α‐MnO 2 /Mn 2 O 3 composite cathode by a molten salt method. This research indicated that Mn 2 O 3 nanoparticles were obtained by a phase transform from α‐MnO 2 nanobelts and the α‐MnO 2 /Mn 2 O 3 composite with the largest mass ratio of Mn 2 O 3 delivers the best electrochemical performance of 162 mAh g −1 at 3 A g −1 and a capacity retention of 86.2 % after 1000 cycles when assembled with modified Zn−C anode [25,26] . Compared to the two‐phase separated composite, a twinborn MnO 2 /Mn 2 O 3 heterojunction reported by Long et al.…”

A two-electron transfer mechanism of the Zn-doped δ-MnO2 cathode toward aqueous Zn-ion batteries with ultrahigh capacity

“…In addition, an outstandingly high specic energy of 628 W h kg À1 was obtained for Zn-doped ZIBs. This is a very high specic capacity and specic energy, clearly surpassing those of most MnO 2 -based and other cathode materials, such as a-(Mn 2 O 3 -MnO 2 ) heterostructures, 32 metalorganic framework Cu 3 (HHTP) 2 , 33 oxygen defect enriched (NH 4 ) 2 V 10 O 25 nanosheets, 34 graphene-wrapped MnO/C, 35 etc., as shown in Table S2. † The two sloping plateaus can be mainly attributed to the redox reactions of Mn 4+ /Mn 3+ and Mn 3+ /Mn 2+ , respectively, which are in accordance with the cyclic voltammetry observations.…”

MnO Stabilized in Carbon‐Veiled Multivariate Manganese Oxides as High‐Performance Cathode Material for Aqueous Zn‐Ion Batteries

“…set the cathode with long-cycle life, large specific capacity and high energy density. [28] Here, we provide an available cooperation of multivariate manganese oxide coated by carbon hybrids (MnO 2 /MnO@C and MnO 2 / Mn 3 O 4 @C) via plasma-assisted milling for Zn-ion cathode, in which multivariate manganese oxide materials convert their instinct electron structures to boost the kinetic ability of ions (Zn 2+ and H + ) insertion/ desertion while the carbon substrates further enhanced the electrical conductivity of MnO x nanocrystals. Especially, the MnO 2 /MnO@C hybrid owns the phase stability behavior due to the available cooperation of Mn (II) and Mn (IV) phases during the reaction of metal ions converting to the metastable state with Zn 2+ / H + insertion into the manganese oxides, which accelerates ion/electron migration rates and promotes charge storage.…”