化學腐蝕對Sn-Co基負極材料結(jié)構和電性能影響.pdf

1、本文通過對Sn-Co-Zn體系和對Sn-Co-Zn/C體系進行化學腐蝕,考察了不同腐蝕程度對于兩種體系的材料的結(jié)構和電性能影響規(guī)律。在Sn-Co-Zn體系中,通過XRD分析發(fā)現(xiàn),SnCoZn0.2-1、SnCoZn0.2-2、SnCoZn0.2-3、SnCoZn0.2-4和SnCoZn0.2的主相均為CoSn相,其中SnCoZn0.2-3、SnCoZn0.2-4和SnCoZn0.2中有CoSn2相的存在。電性能分析表明,SnCoZn0.

2、2-2的首次充電容量最大,為411mAh/g,首次放電容量也最大,為287mAh/g。而SnCoZn0.2-3的循環(huán)性能最好,循環(huán)25次后,保持了首次可逆容量的87.6％。在Sn-Co-Zn/C體系中,根據(jù)XRD分析表明,球磨樣品SnCo/C和腐蝕樣品SnCoZn0.05/C、SnCoZn0.1/C、SnCoZn0.15/C、SnCoZn0.2/C的主相均為CoSn相,腐蝕樣品SnCoZn0.1/C、SnCoZn0.15/C、SnCoZ

3、n0.2/C中含有少量的CoSn2相,腐蝕樣品SnCoZn0.1/C、SnCoZn0.15/C、SnCoZn0.2/C中含有少量Co3Sn2相。SEM分析表明,腐蝕樣品SnCoZn0.05/C、SnCoZn0.1/C、SnCoZn0.15/C、SnCoZn0.2/C較球磨樣品SnCo/C表面結(jié)構和顆粒大小沒有明顯區(qū)別。比表面積分析表明,隨著腐蝕程度的增加,腐蝕樣品SnCoZn0.05/C、SnCoZn0.1/C、SnCoZn0.15/C

4、、SnCoZn0.2/C的比表面積也逐漸增大,且腐蝕樣品的比表面積均大于球磨樣品SnCo/C。電性能分析表明,隨著腐蝕程度的加深,腐蝕樣品SnCoZn0.05/C、SnCoZn0.1/C、SnCoZn0.15/C、SnCoZn0.2/C的循環(huán)性能逐漸增加,均優(yōu)于球磨樣品SnCo/C。隨著腐蝕程度的增加,腐蝕樣品SnCoZn0.05/C、SnCoZn0.1/C、SnCoZn0.15/C、SnCoZn0.2/C的首次充放電容量呈先上升后下降