Potential positive electrodes for high-voltage/high-power magnesium-ion batteries

Research Project

Project/Area Number	22686064
Research Category	Grant-in-Aid for Young Scientists (A)
Allocation Type	Single-year Grants
Research Field	Structural/Functional materials
Research Institution	Kyoto University
Principal Investigator	ICHITSUBO Tetsu 京都大学, 工学研究科, 准教授 (40324826)
Project Period (FY)	2010 – 2011
Project Status	Completed (Fiscal Year 2011)
Budget Amount *help	¥26,520,000 (Direct Cost: ¥20,400,000、Indirect Cost: ¥6,120,000) Fiscal Year 2011: ¥6,500,000 (Direct Cost: ¥5,000,000、Indirect Cost: ¥1,500,000) Fiscal Year 2010: ¥20,020,000 (Direct Cost: ¥15,400,000、Indirect Cost: ¥4,620,000)
Keywords	Mgイオン電池 / 蓄電池 / 多価イオン電池 / 正極材料 / 負極材料 / 電解液 / 二次電池 / マグネシウムイオン / コバルト複合酸化物 / ニッケル複合酸化物 / 充放電特性 / 開回路起電圧
Research Abstract	Magnesium-ion batteries(MIBs) with a Mg-metal negative electrode are expected to combine high energy density and high electromotive force, owing to the divalent ion careers and its low redox potential. However, it has been reported to date that the cell voltage of MIBs is not high enough(~ 1. 5 V), being far below that of lithium-ion batteries(LIBs)(4? 5 V). In this work, we have investigated the potentiality of Mg? Co? O and Mg? Ni? O complex oxides as the positive electrode for MIBs, which are composed of these positive electrodes and a Mg negative electrode in acetonitrile with Mg(ClO4) 2 salt as an electrolyte. These MIBs can exhibit a relatively high open circuit voltage, OCV. However, as the combination of the acetonitrile electrolyte and metal Mg can yield the passivation on the surface of the Mg electrode, we have also checked these materials for a well-established Li ion battery system, and confirmed that the charged battery can show high OCV. In order to attain such a high cell voltage, it would be significant to exploit the unstabilized ionafter charge in the host complex oxide.