【摘要】 采用LiOH·H_O为锂源,化学纯MnO₂（CMD）为锰源,NaJ为添加剂,乙腈为非水介质,在常温常压下合成了锂离子二次电池正极材料Li_0.75Na_0.25MnO_1.92I_0.08化合物,并采用XRD,BET,IEM及电化学测试等手段对该化合物进行了表征.结果表明该化合物原粉呈非晶态超细粉末,平均粒径在45～60nm之间,具有较大的比表面积（35～48m²/g）经260℃真空干燥后,样品转化为纳米晶态,以该化合物作正极材料与Li作对电极构成的锂电池,在1.5～4.3V之间和0.353mA/cm²条件下恒流充放电,首次充放电比容量超过280（mA·h）/g.充放电效率大于95％.循环20次后,其充放电比容量仍大于260（mA·h）/g,是很有应用前景的锂离子二次电池正极材料.更多还原

【Abstract】 The positive electrode (cathode) material Li0.75 Na0.25 MnO1.92 I0.08 for lithium- ion secondary batteries was synthesized using LiOH as the Li source, MnO2 as the Mn source, NaI as an additive, and acetonitrile as non - aqueous solvent at room temperature under atmospheric pressure, and was characterized by XRD, BET and TEM as well as electrochemical testing. The results have demonstrated that Li0.75Na0.25MnO1.92 I0.08 as -synthesized compound is amorphous ultrafine powder with the mean diameter being approximately 45 -60nm. Li0.75Na0.25MnO1.92I0.08 has a large specific surface area (about 35 - 48m2 /g). After dried at 260℃ in vacuum, the sample was transformed into nano - sized crystals, The results of electrochemical studies have revealed that when this dried compound as cathode material and the lithium metal was used as counter -electrode material to compose of a lithium cell, and charged/discharged with a stable current under the conditions of 1.5 - 4. 3V range and 0.353mA/cm2, the first charge and discharge specific capacity was more than 280 (mA·h)/g, and the discharge/charge ratio was more than 95% . After 20 cycles, the charge and discharge specific capacity was also more than 260(mA·h)/g. Therefore, this compound is a cathode material for lithium - ion secondary batteries with remarkable application prospects.更多还原