新型锂离子电池负极及制备工艺.ppt

* * 电化学沉积纳米多孔锡合金锂离子电池负极材料的制备与性能研究 Preparation and characterization of nanoporous tin alloy as anode materials of lithium-ion battery ZHANG Shu-Yong Mar. 13, 2009 1990, commercialization of lithium-ion battery by Sony. Advantages: high specific capacity, long cycle life, high working voltage, no memory effect, less self-discharge, good temperature adaptability, environmental friendliness. Anode materials: Carbonous materials, Si-based materials, Sn-based materials Carbonous materials (碳材料)： 1) Soft carbon(软碳):petroleum coke(石油焦)、carbon fiber(碳纤维)、Mesocarbon Microbeads (中间相碳微球等）、carbon nanotube (碳纳米管) 2）Hard carbon（硬碳） 　　3）Graphite(石墨):natural and artificial 4）Modified carbon(改性碳材料): introduction of B, N, P, K, Al, Co, V, Ni, etc. Main shortcomings: 1) low theoretical capacity: 372 mAh/g 2) high-temperature treatment. 3) co-intercalation of electrolyte with Li+ 4) safety 5) high internal resistance 6) poor cycle life Advantages of alloy anode materials: 1) good precessability 2) easy control of composition and structure 3) low sensitivity to environment 4) fast charge and dischage 5) good safety Advantages of Sn-based materials: (1) optinum operating potential: 1.0～0.3 V vs. Li+/Li，preventing formation of Li dentrite at high charge. (2) No co-intercalation of electrolyte. More solvents can be used. Good safety. (3) high capacity and volume specific capacity: 990 mAh/g for tin alloy and 372 mAh/g for carbonous materials; 1450～1800mAh/ml for tin alloy but 850 mAh/ml for carbonous materials. Problems: large volume change during charge-discharge: 100%～300%. pulverization and worsening of electric contact to current collector. – poor cycle life. Improvements: alloying with Cu, Fe, Sb, Ni, Ca, Mg, Co, Mn, Ag, Zn, S, etc. Binary: Cu-Sn，Sb-Sn, Ni-Sn, Co-Sn，Ag-Sn Ternary: Ag-Sn-Zr，Sb-Sn-Cu，Zn-Sn-Cu Quaternary: Cu-In-Sn-S Syn