Details

Autor(en) / Beteiligte

• Zhou, Shihao
• Wu, Xiangsi
• Du, Hongxia
• He, Zhangxing
• Wu, Xianming
• Wu, Xianwen

Titel

Dual metal ions and water molecular pre-intercalated δ-MnO2 spherical microflowers for aqueous zinc ion batteries

Ist Teil von

• Journal of colloid and interface science, 2022-10, Vol.623, p.456-466

Ort / Verlag

Elsevier Inc

Erscheinungsjahr

2022

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• K+ and Al3+ as the dual metal ions are uniformly pre-intercalated into the framework and the interlayer of δ-MnO2 by hydrothermal method. The energy storage mechanism of δ-MnO2 is the combination of dissolution/deposition and H+/Zn2+ co-insertion/co-extraction. [Display omitted] Layered δ-MnO2 is a promising cathode material for aqueous zinc ion batteries (AZIBs) due to its high theoretical capacity, high operating voltage and low cost. However, the dissolution of MnO2 and the disproportionation of Mn3+ will lead to irreversible reaction and serious structural degradation of the material during cycling process. In this work, the Al3+ pre-intercalated K0.27MnO2·0.54H2O was prepared by a one-step hydrothermal method with citric acid as the complexing agent and weak reducing agent. Based on the pillars of bimetallic ions K+, Al3+ and water, the framework and interlayer of δ-MnO2 is stabilized. Besides, a certain amount of Al3+ facilitates the increase of crystal water compared with the pure K0.27MnO2·0.54H2O, which is not only conducive to promote the construction of porous and loose 3D morphology, but also beneficial to improve the stability of layered structure and accelerate the migration rate of zinc ions. Contributed to the dissolution/deposition reaction mechanism combined with H+/Zn2+ co-insertion/co-extraction mechanism, it has achieved the high capacity with the maximum reversible specific capacity of 269.5 mAh g−1 at 0.5 A g−1 and excellent stability with 205.8 mAh g−1 even after 300 cycles in Zn//Al-KMO battery.