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Aqueous zinc‐ion batteries are promising energy storage devices due to their low cost, good ionic conductivity, and high safety. Conductive polyaniline is a promising cathode because of its redox activity, but because the neutral electrolyte protonates only weakly, it displays limited electrochemical activity. A polyaniline cathode is developed with proton self‐doping from manganese metal–organic frameworks (Mn–MOFs) that alleviates the deprotonation and electrochemical activity concerns arising during the charge/discharge process. The MOFs carboxyl group provides protons to prevent deprotonation and allows the polyaniline to reach a high zinc storage redox activity. The proton self‐doped polyaniline cathode has a superior specific capacity (273 mAh g−1 at 0.5 A g−1), a high rate property (154 mAh g−1 at 20 A g−1), and excellent cyclability retention (87% over 4000 cycles at 15 A g−1). This research provides fresh insight into the development of innovative polymers as cathode materials for high‐performance AZIBs. [ABSTRACT FROM AUTHOR]

A hierarchical spheroidal MnO@C heterogeneous interface as a cathode material for AZIBs and synthesized through a MOF, which exhibits the excellent cycling stability. [Display omitted] Aqueous zinc-ion batteries (AZIBs) have shown great potential as energy storage devices owing to their high energy density, low cost, and low toxicity. Typically, high performance AZIBs incorporate manganese-based cathode materials. Despite their advantages, these cathodes are limited by significant capacity fading and poor rate performance due to the dissolution and disproportionation of manganese. Herein, hierarchical spheroidal MnO@C structures were synthesized from Mn-based metal–organic frameworks, which benefit from a protective carbon layer to prevent manganese dissolution. The spheroidal MnO@C structures were incorporated onto a heterogeneous interface to act as a cathode material for AZIBs, which exhibited excellent cycling stability (160 mAh g−1 after 1000 cycles at 3.0 A g−1), good rate capability (165.9 mAh g−1 at 3.0 A g−1), and appreciable specific capacity (412.4 mAh g−1 at 0.1 A g−1) for AZIBs. Moreover, the Zn2+ storage mechanism in MnO@C was comprehensively investigated using ex-situ XRD and XPS studies. These results demonstrate that hierarchical spheroidal MnO@C is a potential cathode material for high-performing AZIBs. [ABSTRACT FROM AUTHOR]

Aqueous zinc-ion batteries is considered as a promising system for large scale electrochemical energy storage system owing to their intrinsic safety, and low cost. Nevertheless, the industrialization process is slow due to the constraints of high-performance cathode materials. Adjusting the layered structure of V 2 O 5 through metal ion or polymer intercalation can effectively improve low electron conductivity, vanadium dissolution, and slow ion transport kinetics. Herein, the conductive polymer polypyrrole-intercalated V 2 O 5 ·H 2 O (PVOH) was successfully prepared via simple hydrothermal method and following interface polymerization reaction. Getting benefit from the insertion of polypyrrole, the prepared PVOH composite material achieves a V 2 O 5 cathode with a more open structure, rich active sites, and greater stability, allowing for an expanded crystal plane spacing of 14.5 Å. Therefore, the PVOH electrode demonstrates a discharge capacity of 475 mAh g−1 and a cycling stability of 95 % capacity retention after 2000 cycles. The intercalating conductive polymers strategy can become a new approach to improve the electrochemical behavior of vanadium oxide cathodes. [Display omitted] • The conductive polymer polypyrrole-intercalated PVOH was successfully prepared. • The PVOH has a more open structure, rich active sites, and an expanded crystal plane spacing of 14.5 Å. • The PVOH electrode demonstrates a discharge capacity of 475 mAh g−1 at 0.1 A g−1. • A detailed investigation is conducted on the co-insertion mechanism of Zn2+/H+ by the different ex-situ characterization. [ABSTRACT FROM AUTHOR]

Abstract Traditional approaches to recycle and regenerate spent lithium-ion batteries by leaching are polluted and complicated. In this study, a green and simple technique has been provided to regenerate spent LiNi 0.5 Co 0.2 Mn 0.3 O 2 cathode material, besides, the regenerated mechanisms are investigated. Studies indicate that lost lithium ions in material lattice are replenished by added lithium, meanwhile, insulting impurities on particle surface remove basically, cracked and broken particles disappear during the regeneration process. Electrochemical tests demonstrate that the performances of regenerated material improve significantly. The discharge capacities are 164.6 mAh g−1 at 0.1 C rate and 147 mAh g−1 at 1 C rate, respectively. They still could deliver a discharge capacity of 131 mAh g-1 with a high capacity retention rate of 89.12% after 100 cycles at 1 C, which can be considered as a preferable electrical energy storage system. The improved electrochemical performances prove a facial and effective regeneration process. [ABSTRACT FROM AUTHOR]

• A three-dimensional mesoporous microsphere structural β-MnO 2 /PPy composite was obtained using a facile hydrothermal method. • The electric PPy nanowires linked each β-MnO 2 nanorods to significantly enhance the energy storage behavior of β-MnO 2. • The total capacity was dominated by the synergistic effect between the diffusion-controlled and capacitive behavior. [Display omitted] Mn-based materials as a cathode have drawn much attention in aqueous zinc-ion batteries (AZIBs) for its advantages of low cost and environmental friendliness. However, the sluggish reaction kinetics and low structural stability still limit the electrochemical application of Mn-based materials. Herein, a β-MnO 2 / polypyrrole (PPy) composite was synthesized using a facile hydrothermal method. It delivered a remarkable specific discharge capacity of 361.8 mAh g−1 at a current density of 0.2 A g−1 and great rate performance compared to pure MnO 2 powder. And morphological and electrochemical characterizations revealed that the enhanced electrochemical performance of β-MnO 2 /PPy composite was mainly attributed to the high conductivity of PPy nanowires and the 3D mesoporous microsphere structure, which was assembled by β-MnO 2 nanorods and PPy nanowires. This article provided a new sight of synthesizing Mn-based materials/conducting polymer composites for high-performance cathode in zinc-ion batteries. [ABSTRACT FROM AUTHOR]