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不同維度矽/碳奈米複合材料的製備與鋰離子電池負極材料應用
Thesis

不同維度矽/碳奈米複合材料的製備與鋰離子電池負極材料應用

林家聲
Masters, 國立清華大學, 生醫工程與環境科學系
2015

Abstract

鋰離子電池 負極材料 奈米矽 奈米碳管 還原氧化石墨烯 規則中孔洞碳材 Lithium ion battery anode materials Silicon Carbon nanotubes Graphene Mesoporous carbons
Lithium ion batteries (LIBs) play an important role in our daily life. It has been used for cell phone, ipad, laptop and battery electric vehicle. It is one of the richest topics to improve the battery performance in nowadays. Silicon is present in the earth’s crust at 27.7 % of the total and, after oxygen, is the second most abundant element. In addition, Silicon has been widely used as the anode material for lithium ion batteries (LIBs) because of the huge theoretical capacity (~4200 mAh/g) compared with commercial carbon material (~372 mAh/g) and relatively low discharge potential (~0.5V VS. Li/Li+). However, the large volume expansion (~ 400%) after charge-discharge processes hampers the application of silicon to LIBs. In this study, we have synthesized successfully that the combination of Si with different dimensional carbon materials including carbon nanotubes (1D), graphenes (2D), and mesoporous carbons (3D) can minimize the volume expansion, resulting in the enhancement of electrochemical performance of silicon-based electrodes. After 100 cycles, the capacity of 1D, 2D and 3D nanocomposites are ~800 mAh/g, ~1000 mAh/g and ~1300 mAh/g respectively. The coulomb efficiency is above 97% remarkably. It shows our different dimensional carbon materials can be maintained structure after charge-discharge and excellent electrochemical stability. In the future, it can provide the method to improve materials which have the large volume expansion after charge-discharge processes, for example Sn, Sb, Mg and Al.

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