Synthesis of porous carbon electrode material with low side reaction with Li-ions

2022 Fiscal Year Final Research Report

• Project/Area Number: 21K20560
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund
• Review Section: 0502:Inorganic/coordination chemistry, analytical chemistry, inorganic materials chemistry, energy-related chemistry, and related fields
• Research Institution: Nagasaki University
• Principal Investigator: Notohara Hiroo 長崎大学, 工学研究科, 助教 (20908595)
• Project Period (FY): 2021-08-30 – 2023-03-31
• Keywords: 多孔性カーボン / 不可逆容量 / 全固体電池 / Liイオン電池

Outline of Final Research Achievements

Porous carbon is an effective host material for high-capacity active materials in all-solid-state batteries. However, irreversible capacity due to side reactions during the initial lithiation process is a severe problem for electrode materials. We investigated the cause of the irreversible reactions through structural observations of the porous carbon electrode during the lithiation-delithiation process. The main cause of the irreversible capacity is that active gases such as oxygen in the battery cell and oxygen-containing functional groups on the porous carbon surface react with Li ions and precipitate on the carbon surface. We succeeded in significantly reducing the irreversible capacity by controlling the atmosphere inside the battery cell and hydrogen-terminating the surface functional groups of the porous carbon.

Free Research Field

電気化学，ナノ構造解析

Academic Significance and Societal Importance of the Research Achievements

多孔性カーボン材料はSnO2などの高容量活物質のホスト材料として有効であり，全固体電池電極として高い充放電特性を発現することが明らかとされている。しかしながら，初回充放電サイクルにおける不可逆容量が大きく，充放電効率の低さが課題である。本研究では，この不可逆容量の要因を特定し，初回充放電の効率を向上させることに成功した。これにより，多孔カーボン電極を用いた高容量でサイクル特性に優れた全固体電池の創製が期待される。