Science Bulletin, 17 January, 2025, DOI：https://doi.org/10.1016/j.scib.2024.10.034

In situ synthetic C encapsulated δ-MnO2 with O vacancies: a versatile programming in bio-engineering

Wei Lv, Zilei Shen, Junlin Liu, Xudong Li, Fang Ding, Dongyue Zhang, Licheng Miao, Xuefeng Lyu, Ruijie Li, Miaomiao Wang, Yiming Li, Jingwen Meng, Chao Xu

Abstract

In this study, we successfully synthesized a δ-MnO₂ cathode with O vacancies, encapsulated by C derived from pyromellitic acid, using a facile hydrothermal method followed by annealing in an Ar atmosphere. The cathode’s structural stability and charge transfer kinetics are enhanced by inhibiting the formation of the by-product Zn₄SO₄(OH)₆·4H₂O, regulating the Mn valence state, and suppressing the Jahn–Teller effect through the synergy of C encapsulation and O vacancies. This results in remarkable electrochemical performance, including a large capacity of 421.2 mAh g⁻¹ at 0.1 A g⁻¹, a high specific energy density of 595.53 Wh kg⁻¹, and exceptional long-cycle life stability with 90.88% over 4000 cycles at 10 A g⁻¹, together with superior coulombic efficiency (～100%) in pure ZnSO₄ electrolyte. Moreover, the cathode materials demonstrate specific antitumor efficacy. In brief, this work introduces an in situ synthetic C encapsulated δ-MnO2 with O vacancies expected to be applied in both large-scale energy storage and biomedicine.

Article link：https://www.sciencedirect.com/science/article/pii/S2095927324007965?via%3Dihub