Development of novel cathode materials for sodium-ion-secondary battery based on ionic model

2016 Fiscal Year Final Research Report

• Project/Area Number: 15K13513
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Condensed matter physics II
• Research Institution: University of Tsukuba
• Principal Investigator: KOBAYASHI Wataru 筑波大学, 数理物質系, 助教 (70434313)
• Research Collaborator: MORITOMO Yutaka 筑波大学, 数理物質系, 教授 (00283466) ; NIWA Hideharu 筑波大学, 数理物質系, 助教 (50704566)
• Project Period (FY): 2015-04-01 – 2017-03-31
• Keywords: 層状酸化物 / ナトリウムイオン二次電池 / 圧力効果 / EXAFS解析

Outline of Final Research Achievements

Cathode materials for sodium-ion-secondary batteries (SIBs) have been extensively studied since the discovery of the hard carbon as an anode material for SIBs. We studied pressure (P) effects on battery voltage (V) and crystal structure of layered NaMO2 (M=Cr, Fe, Co) to test the ionic model and to develop cathode materials with high value of V. We succeeded in measuring the battery voltage and crystal structure of NaMO2 (M=Cr, Fe, Co) up to 2.0 GPa. With increasing P, V monotonically increases. Using the ionic model together with crystallographic date under high P, we reproduced the increase in V. Under high P, oxygen anions in NaMO2 relatively get close to sodium cations, which strongly traps the sodium cation leading to the high V.

Free Research Field

物性物理学