The study for charge transfer reaction in Li-ion battery using first-principles calculation combined with implicit salvation model

2023 Fiscal Year Final Research Report

• Project/Area Number: 20K15376
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 36020:Energy-related chemistry
• Research Institution: The University of Tokyo
• Principal Investigator: Haruyama Jun 東京大学, 物性研究所, 助教 (80772003)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: Liイオン電池 / 第一原理計算 / 電気化学

Outline of Final Research Achievements

Lithium-ion batteries (LIBs) have attracted considerable attention for use in electric vehicles due to their excellent characteristics of energy density and charge/discharge cycles. For realizing rapid charge/discharge reactions, however, it is necessary to understand a microscopic perspective for rate-determining step. This research topic mainly focuses on the reactions associated with Li diffusion in graphite electrodes. We treated the mechanism of structure change and discussed the thermodynamic stability of high-stage Li-intercalated graphite from the free energy estimated by first-principles calculations. As a result, we found the most stable state at LiC18 composition and the composition of layered structure transition of graphite, which results are highly consistent with the experimental observations of operando synchrotron radiation X-ray diffraction.

Free Research Field

計算科学

Academic Significance and Societal Importance of the Research Achievements

Li挿入に伴うグラファイトのステージ構造変化はLiイオン電池研究の初期から行われている古典的なテーマであるが, 本研究課題はより高ステージの構造変化を扱った. 結果第一原理計算の精密な自由エネルギーで実験の多くを説明することが出来, 第一原理自由エネルギー解析の有効性を示した. 今後はより解析を進めることで, グラファイト内のLi拡散経路の精査から急速な充放電実現のための知見が得られると期待される.