由於鉀含量豐富且價格低廉，因此鉀離子電池作為可替代鋰離子電池的候選人而越來越受到關注。在這次研究中，BiSbSe3/石墨複合材料藉由高能量球磨方法合成出來並首次用來當作鉀離子電池的負極材料。此材料在10 A g-1下具有116 mA h g-1的優異倍率能力，並在500 mA g-1下循環500次後仍保有250 mA h g-1的高電容量。除此之外，還藉由in-situ XRD以及ex-situ TEM的技術研究BiSbSe3在過程中的反應機制以及循環伏安法、GITT技術分析動力學。本次研究還報導了Cu3BiS3第一次被當作鉀離子電池負極材料。此材料較二元的CuS和Bi2S3擁有更好的循環穩定性。藉由ex-situ XRD、ex-situ HRXPS以及ex-situ TEM分析充放電過程中的反應機制，並藉由第一原理計算、SIMS技術研究Cu3BiS3擁有較好循環穩定性的原因。此項工作可能為新型高效能三元型鉀離子電池負極材料的開發開闢一條新的道路。

Due to the abundance and low price of potassium, potassium-ion batteries have received increasing attention as a candidate to replace lithium-ion batteries. In this study, BiSbSe3/graphite composites were synthesized by high-energy ball milling and used for the first time as anode materials for potassium-ion batteries. This material exhibits an excellent rate capability of 116 mA h g-1 at 10 A g-1 and retains a high capacitance of 250 mA h g-1 after 500 cycles at 500 mA g-1. In addition, the reaction mechanism of BiSbSe3 in the charging and discharging process was studied by in-situ XRD and ex-situ TEM, and the kinetics were analyzed by cyclic voltammetry and GITT techniques. This study also reported that Cu3BiS3 was used as an anode material for potassium-ion batteries for the first time. This material has better cycling stability than binary CuS and Bi2S3. The reaction mechanism during the charge-discharge process was analyzed by ex-situ XRD, ex-situ HRXPS and ex-situ TEM, and the reason why Cu3BiS3 had better cycling stability was investigated by first-principle calculations and SIMS technology. This work may open a new avenue for the development of new high-efficiency ternary potassium-ion battery anode materials.

中文摘要 I
Abstract II
List of figures IV
Chapter 1. Introduction 1
1.1 Prospects and challenges of potassium ion batteries 1
1.2 Anode materials for potassium ion batteries 1
1.3 Concept of Bi-Sb-Se ternary alloy conversion anode material 4
1.4 Concept of Cu-Bi-S ternary alloy conversion anode material 5
Chapter 2. Experimental section 7
2.1 Materials 7
2.2 Synthesis of BiSbSe3 7
2.3 Synthesis of BiSbSe3/G 7
2.4 Material characterization 7
2.5 Electrochemical measurement 8
Chapter 3. Result and discussion 9
3.1 Morphology 9
3.2 Structure characterization 10
3.3 Electrochemical performance 12
3.4 Mechanism 15
3.5 Kinetic 18
Chapter 4. Synthesis of copper-bismuth-sulfur ternary compound 21
4.1 Materials 21
4.2 Synthesis of Cu3BiS3 21
4.3 Synthesis of Cu3BiS3/G 21
4.4 Material characterization 21
4.5 Electrochemical measurement 22
Chapter 5. Result and discuss of Cu3BiS3 as a novel potassium ion battery anode 23
5.1 Morphology of Cu3BiS3 23
5.2 Structure characterization of Cu3BiS3 25
5.3 Electrochemical performance of Cu3BiS3 26
5.4 Mechanism of Cu3BiS3 28
5.5 Ex-situ TEM analysis of Cu3BiS3 31
5.6 Comparison of binary and ternary systems and DFT calculation 33
Conclusion 35
Reference 36

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