鋰離子電池正極材料lini,0.8co,0.1mn,0.1o,2的合成及其電化學(xué)性能研究

1、湘潭大學(xué)碩士學(xué)位論文鋰離子電池正極材料LiNiCoMnO的合成及其電化學(xué)性能研究姓名：王希敏申請(qǐng)學(xué)位級(jí)別：碩士專業(yè)：無(wú)機(jī)化學(xué)指導(dǎo)教師：王先友20070501鋰離子電池正極材料 LiNi0.8Co0.1Mn0.1O2 的合成及其電化學(xué)性能研究 III ABSTRCT Lithium-ion batteries (LIB) with high energy density, power capability and long cycle l

2、ife are used to power portable electronic devices such as cellular phones and laptop computers and have long been considered as possible power source for electric vehicle (EV), hybrid electric vehicle (HEV) and high effi

3、ciency energy-storage systems. Layered LiCoO2 is the most widely used cathode material in the present-day commercial Li-ion batteries. However, due to its high cost and toxicity, considerable effort has been expended ove

4、r the past decade to find possible alternatives to LiCoO2. Recently, LiNi0.8Co0.1Mn0.1O2 as a special case among the Li[Ni1-2xCoxMnx]O2 series which x is 0.1 has attracted a great deal of interest in the investigation o

5、f cathode materials of LIB to replace the presently popular LiCoO2 because the combination of Ni, Co, Mn can provide advantages such as high reversible capacity, stable cycling performance, good thermal stability, excell

6、ent rate capability and low cost. It is considered to be one of the best candidates of positive electrode material for hybrid electric vehicle (HEV) power source system. In this dissertation，the studies on the synthesis

7、, morphology, structure and electrochemical performance of LiNi0.8Co0.1Mn0.1O2 as cathode materials for lithium ion batteries were carried out systemically and in detail. In this paper, the uniform spherical metal

8、hydroxide (Ni0.8Co0.1Mn0.1)(OH)2 was prepared via hydroxide co-precipitation as precursor. This paper represents details of the optimized spherical (Ni0.8Co0.1Mn0.1)(OH)2 formation process by control reaction time, pH, a

9、mount of chelating agent, etc., during co-precipitation reaction. The results indicated that the optimum conditions for spherical (Ni0.8Co0.1Mn0.1)(OH)2 were that the pH of the aqueous solution was 11.5, the NH3/M was 2

10、.5 and the reaction time was 16h. Layered spherical LiNi0.8Co0.1Mn0.1O2 powders with high tap-density were successfully synthesized by mixing uniform co-precipitated spherical (Ni0.8Co0.1Mn0.1)(OH)2 with LiOH?H2O f

11、ollowed by heat-treatment. The mixture was pre-heated at 480℃ and kept in this temperature for 5h, then kept at 650for 9h. The ℃effects of calcination temperature, time and Li/(Ni+Mn+Co) ratio on electrochemical propert

12、ies of the LiNi0.8Co0.1Mn0.1O2 were studied intensively. The results showed that the sample of LiNi0.8Co0.1Mn0.1O2 which were sintered for 16h at 750℃ in a flowing oxygen atmosphere exhibited the best electrochemical per

13、formance. In this study, the morphology, tap-density, structure and electrochemical performance of the sample LiNi0.8Co0.1Mn0.1O2 obtained at optimal conditions have been further studied. The particle shape is still sphe