Development of vanadate glass with high electrical conductivity and its application for a cathode active material of secondary batteries

2017 Fiscal Year Final Research Report

• Project/Area Number: 15H03882
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Device related chemistry
• Research Institution: Tokyo Metropolitan University
• Principal Investigator: KUBUKI Shiro 首都大学東京, 理工学研究科, 准教授 (90321489)
• Co-Investigator(Kenkyū-buntansha): 岡田 重人 九州大学, 先導物質化学研究所, 教授 (10304841) ; 吉岡 聰 九州大学, 工学研究院, 助教 (50452818)
• Co-Investigator(Renkei-kenkyūsha): NISHIDA Tetsuaki 近畿大学, 工学部, 教授 (10112286)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: メスバウアー分光法 / バナジン酸塩ガラス / 二次電池正極材

Outline of Final Research Achievements

In this project, we investigated a relationship between the structure and electrical properties of sodium phosphovanadate glass with the composition of xNa2O・10P2O5・(90-x)V2O5 ('x' = 5-45 mol%, abbreviated as xNPV) as a cathode active material with high performance. DTA curves of xNPV glass showed a decrease in glass transition temperature (Tg) from 235 to 195 oC, while electrical conductivity (EC) decreased from 3.6×10-6 to 6.4×10-8 S cm-1 with the increase of‘x’from 5 to 45. These results suggested that the cleavage of the 3D-network structure caused the decrease in Tg and EC . Charge-discharge capacity of as-quenched xNPV glass showed a larger initial capacity than that of heat-treated samples. In particular, 45NPV glass had a large initial capacity of 258 mAh/g while it showed a very small irreversible capacity (21 mAh/g). These results suggest that 45NPV glass is a one of the good candidates for a cathode active material of sodium ion batteries.

Free Research Field

無機材料化学