Valence Engineering via In Situ Carbon Reduction on Octahedron Sites Mn3O4 for Ultra‐Long Cycle Life Aqueous Zn‐Ion Battery

By Qiuyang Tan, Xueting Li, Baohui Zhang, Xu Chen, Yawen Tian, Houzhao Wan, Lishang Zhang, L. Miao, Cong Wang, Yisheng Gan and 3 more. Advanced Energy Materials, 2020

311 citations recorded by the source corpus.

In recent years, rechargeable aqueous zinc‐ion batteries (ZIBs) have received much attention. However, the disproportionation effect of Mn2+ seriously affects the capacity retention of ZIBs during cycling. Here, the capacity retention of the Mn3O4 cathode is improved by effective valence engineering. The valence engineering of Mn3O4 is caused by bulk oxygen defects, which are in situ derived from the Mn‐metal organic framework during carbonization. Bulk oxygen defects can change the (MnO6) octahedral structure, which improves structural stability and inhibits the dissolution of Mn2+. The ZIB assembled from bulk oxygen defects Mn3O4@C nanorod arrays (Od‐Mn3O4@C NA/CC) exhibits an ultra‐long cycle life, reaching 84.1 mAh g−1 after 12 000 cycles at 5 A g−1 (up to 95.7% of the initial capacity). Furthermore, the battery has a high specific capacity of 396.2 mAh g−1 at 0.2 A g−1. Ex situ characterization results show that initial Mn3O4 is converted to ramsdellite MnO2 for insertion and extraction of H+ and Zn2+. First‐principles calculations show that the charge density of Mn3+ increases greatly, which improves the conductivity. In addition, the flexible quasi‐solid‐state ZIB is successfully assembled using Od‐Mn3O4 @ C NA/CC. Valence engineering induced by bulk oxygen defects can help develop advanced cathodes for aqueous ZIB.

Subfields: Electrical and Electronic Engineering

View Paper: https://www.semanticscholar.org/paper/99bcbf772527286a6bd0f94049f0777b2559588d