新铁源制备高振实密度LiFePO_4/C正极材料  

Preparation of High Tap-Density LiFePO_4/C by New Iron Source

作　　者：郭孝东[1] 赵浩川[1] 文嘉杰[1] 钟本和[1] 刘恒[2] 唐艳[1] 

机构地区：[1]四川大学化学工程学院教育部磷资源利用中心,四川成都610065 [2]四川大学材料科学与工程学院,四川成都610065

出　　处：《高校化学工程学报》2011年第2期314-318,共5页Journal of Chemical Engineering of Chinese Universities

基　　金：国家科技支撑计划(2007BAQ01055);四川省自然科学基金(50574063)

摘　　要：以铁粉为铁源,LiH2PO4和酒石酸分别作为锂源和络合剂,采用机械活化法制备磷酸亚铁锂正极材料,制备出的材料具有振实密度较高的特点,有利于提高材料的体积能量密度。同其它制备高振实密度磷酸亚铁锂的方法相比较,该方法无需预先将原料制备成高振实密度、球形的中间体,因此大大地简化了工艺,易于实现工业化。研究认为机械活化时间对材料的影响较大,因此重点考查了制备过程中机械球磨活化时间对材料物化性质的影响,发现球磨时间过短导致原材料反应活性较低、产物中出现杂相物质、颗粒粒径较大且分布不均,从而导致电化学性能较差,而球磨时间对材料的振实密度影响不大。在球磨活化原料6 h,于700℃高温反应10 h后制得的磷酸亚铁锂正极材料振实密度到达1.84 g·cm-3,正极材料的体积能量密度高达870 W·h·L-1,具有较高的实用价值。The iron powder,LiH2PO4 and tartaric acid were employed as raw materials to prepare the high tap-density lithium iron phosphate cathode materials（LiFePO4/C） by mechanical activation method of ball-milling.Compared with other conventional preparation method,the proposed method does not need to prefabricate the spherical or high-density precursor,thus simplifying the preparation process and being easy to be used for industrial production.Since the experiments show that the mechanical activity time plays relatively important role for the performance of the prepared LiFePO4/C,this study will stress upon the effects of the ball-milling time on the physicochemical performance of the product.It was found that,the ball-milling time has no impact on the tap-density of the end product,but if the ball-milling time is too short,the raw materials can not fully be activated and some impurities phases emerge;at the same time,the grains of the product are larger and particle size distribution is wider.All the above lead to cause the prepared LiFePO4/C to have bed electrochemical performance.With the optimum preparation conditions of 6 h ball-milling and 10 h calcination at 700℃,an excellent product sample with tap-density of 1.84 g cm 3 was obtained,and its volume energy density can also reach up to 870 W h L 1.

关 键 词：磷酸亚铁锂 铁源 振实密度 机械活化 

分 类 号：TM2[一般工业技术—材料科学与工程]