高锰酸钾返滴定法和硫酸亚铁铵滴定法联合测定尖晶石型锰酸锂中锰平均价态  

Determination of average valence of manganese in spinel lithium manganate by potassium hypermanganate back titration coupled with ammonium ferrous sulfate titration

作　　者：田建坤[1] 张利敏 张海朗 邹爱兰[3] 

机构地区：[1]信阳职业技术学院化工系,河南信阳464000 [2]江南大学化学与材料工程学院,江苏无锡214122 [3]中南大学资源加工与生物工程学院,湖南长沙410083

出　　处：《冶金分析》2011年第9期63-66,共4页Metallurgical Analysis

摘　　要：采取一次称样,先用高锰酸钾-草酸钠返滴定法测定了尖晶石型锰酸锂样品中高价锰的还原电子的物质的量,而后在磷酸介质中,用高氯酸-硫酸亚铁铵滴定法测定了溶液中的总锰量,减去加入高锰酸钾中的锰量即为样品中的锰量,结合还原电子的物质的量计算得到了尖晶石型锰酸锂中锰的平均价态。对测定锰平均价态的条件,如水浴温度,草酸钠、磷酸和高氯酸的用量进行了详细研究,并确定了最佳实验条件。将该方法应用于掺杂尖晶石型锰酸锂中锰平均价态的测定,所得结果在3.57～3.69之间,与掺杂锰酸锂中锰化合价高于3.5结果一致,相对标准偏差(RSD,n=6)在0.26%～0.30%之间。After a single weighting,the amount of substance of reducing electron for high-valence manganese in spinel lithium manganate was determined by potassium permanganate-sodium oxalate back titration method firstly,and then,the content of total manganese in solution was determined by perchloric acid-ammonium ferrous sulfate titration method in phosphoric acid medium.By subtracting the manganese in potassium permanganate,the content of manganese in sample could be obtained.Combining with the amount of substance of reducing electron,the average valence of manganese in spinel lithium manganate was calculated.The determination conditions were investigated in detail,including the water bath temperature,dosage of sodium oxalate,phosphoric acid and perchloric acid.The optimized experimental conditions were obtained.The proposed method has been applied to the determination of average valence of manganese in mixed spinel lithium manganate.The results were between 3.57-3.69,which was consistent with the fact that the valence of manganese in mixed lithium manganate was higher than 3.5.The relative standard deviations（RSD,n=5） were 0.26%-0.30%.

关 键 词：尖晶石型锰酸锂 锰平均价态 滴定法 锂离子电池 正极材料 

分 类 号：TM912[电气工程—电力电子与电力传动]