Preparation of Si-Based Anode Active Materials for Next-Generation Lithium-Ion Batteries and Optimization of Electrode/Ionic Liquid Electrolyte Interphase

2019 Fiscal Year Final Research Report

• Project/Area Number: 17H03128
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Inorganic industrial materials
• Research Institution: Tottori University
• Principal Investigator: SAKAGUCHI Hiroki 鳥取大学, 工学研究科, 教授 (00202086)
• Co-Investigator(Kenkyū-buntansha): 道見 康弘 鳥取大学, 工学研究科, 助教 (50576717) ; 薄井 洋行 鳥取大学, 工学研究科, 准教授 (60423240)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: リチウムイオン電池 / 負極 / ケイ素 / イオン液体 / コンポジット化 / ドーピング

Outline of Final Research Achievements

We synthesized anode active materials for lithium-ion batteries and investigated their electrochemical performances. Ternary-silicide/Si composite electrodes exhibited better cycle life compared to binary-silicide/Si electrodes. We optimized coating conditions of Ni-P on Si particles, and then, the Ni-P/Si electrodes annealed at around 1173 K showed a superior cycling performance. Additionally, a 100 ppm P-doped Si electrode exhibited longer cycle life in a certain ionic-liquid electrolyte compared to a Si-alone electrode. The Si layer thickness was not solely proportional to the amount of Li-rich phase (LixSi, x = 2.00-3.75). As well as the amount, the distribution of the phase should affect the increase in the Si layer thickness. When the Li-rich phase is inhomogeneously distributed, a large local strain accumulates, and a dramatic increase in the Si thickness should occur.

Free Research Field

無機材料化学

Academic Significance and Societal Importance of the Research Achievements

本研究ではリチウム二次電池 (LIB)用Si系負極のLi吸蔵－放出挙動を明らかにした．この成果は学術的に大変興味深く新たな材料を創製するうえで重要な設計指針となり得る．また，コンポジット電極の性能を実用に供することの出来るレベルまで向上させることが出来た．このような成果は高エネルギー密度，長寿命および高い安全性を兼ね備えた次世代LIBの開発に貢献できるものと考えている．