Lee, Boeun Yoon, Chong Seung Lee, Hae Ri Chung, Kyung Yoon Cho, Byung Won Oh, Si Hyoung 2024-01-20T09:03:32Z 2024-01-20T09:03:32Z 2021-09-02 2014-08-14 2045-2322 https://pubs.kist.re.kr/handle/201004/126468 Zn-ion batteries are emerging energy storage systems eligible for large-scale applications, such as electric vehicles. These batteries consist of totally environmentally-benign electrode materials and potentially manufactured very economically. Although Zn/alpha-MnO2 systems produce high energy densities of 225 Wh kg(-1), larger than those of conventional Mg-ion batteries, they show significant capacity fading during long-term cycling and suffer from poor performance at high current rates. To solve these problems, the concrete reaction mechanism between alpha-MnO2 and zinc ions that occur on the cathode must be elucidated. Here, we report the intercalation mechanism of zinc ions into alpha-MnO2 during discharge, which involves a reversible phase transition of MnO2 from tunneled to layered polymorphs by electrochemical reactions. This transition is initiated by the dissolution of manganese from alpha-MnO2 during discharge process to form layered Zn-birnessite. The original tunneled structure is recovered by the incorporation of manganese ions back into the layers of Zn-birnessite during charge process. English NATURE PUBLISHING GROUP LITHIUM BATTERIES CRYSTAL-STRUCTURE ION BATTERY TODOROKITE OXIDE BIRNESSITE CATHODE CHALCOPHANITE ZNMN3O7.3H2O NANOWIRES Electrochemically-induced reversible transition from the tunneled to layered polymorphs of manganese dioxide Article 10.1038/srep06066 1 SCIENTIFIC REPORTS, v.4 SCIENTIFIC REPORTS 4 scie scopus 000340675000010 2-s2.0-84906225566 Multidisciplinary Sciences Science & Technology - Other Topics Article LITHIUM BATTERIES CRYSTAL-STRUCTURE ION BATTERY TODOROKITE OXIDE BIRNESSITE CATHODE CHALCOPHANITE ZNMN3O7.3H2O NANOWIRES rechargeable zinc battery manganese dioxide phase transition cathode