Preparation of lithium-alloyable metalloid nanoparticles/porous carbon spheres as anode materials

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K05094
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 26020:Inorganic materials and properties-related
• Research Institution: Gunma National College of Technology
• Principal Investigator: Ota Michiya 群馬工業高等専門学校, 物質工学科, 教授 (40168951)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 高分子小球体 / 膨潤多孔質炭素 / 有機半金属化合物 / 金属ナノ粒子 / 急速熱分解 / 放電容量 / 半金属系ナノ粒子／多孔質炭素小球体負極材料 / 負極電極

Outline of Final Research Achievements

Lithium-alloyable metalloid nanoparticles-supported porous carbons were prepared. Metalloid particles were formed by rapidly pyrolysis after adsorption of organometallic compounds containing B, Si, or Al on swollen porous carbon particles. Si particles prepared with dichlorodiphenylsilane were less than 100 nm in diameter, and Si-O bond was observed on the surface. When pyrolytic carbon was directly coated, the sample containing 8 wt% of Si showed an initial discharge capacity of 210 mAh/g, and further decrease in discharge capacity was suppressed. B nanoparticles had difficulty in find on the particle surface, although the existence of B was detected from ash. Nano- to micro-sized Al particles were observed on the surface of the swollen porous carbon particles, but Al-O bonds on the Al particle surface were also deteced. These results suggest that the Si nanoparticles supported porous carbons coated with pyrolytic carbon have the possibility as a suitable negative electrode material.

Free Research Field

工学

Academic Significance and Societal Importance of the Research Achievements

１）学術的意義：従来のケイ素(Si)含有負極電極では炭素粉末とSiナノ粒子(SiNP)との混合物を使用して放電容量を高くする方法が多かったが、NPサイズのバラツキと表面の酸化被膜の形成が課題であった。本研究では膨潤多孔質炭素の細孔内でSiNPを調製したのち熱分解炭素被覆を行ったことでバラツキ・炭素との密着性・酸化が抑制され、特性低下の抑制が期待される。
２）社会的意義：従来の黒鉛系負極では最大放電容量が372mAh/gと限界にあるが、リチウム合金を形成するSiNPを内包することで容量と安定性が改善され、急速充電が可能な大型蓄電池としての期待が高まる。