The effect of doping on the electrochemical performance was studied for spinel type LiLo2MxMn2-QyO- used as cathode material in lithium-ion battery. TG/DTA curves of the precursor (the raw materials) doped with different elements were studied. The spinel materials Lil. 02Mn204, Li1. 02Coo. 02Cro. olLao. olMnL96Fo. 0203. 98, Li0. o2Coeo2Cro. ol L, %. oiMnl. 96Clo. oO3., Lilo2Coo1. 02LaLo2Mnl. 97Clo. 0203. 98, Lil. 02Coeo2CreolMnL9704, were prepared by solid-state reaction method after the pretreatment of conversion under low temperature and uniform mixing. X-ray diffraction patterns showed that all the samples had perfect spinel structure. SEM indicated that the particles of the samples had uniform size and were distributed evenly. The results of the charge/discharge curves showed that Lil. ozCoo. ozCro. olLao. olMn196Fo. ozO3 had better performance than other materials according to the inhibition of decline of reversible capacity of spinel LiLozMMnz-Q3-O4,.. Therefore, cycle performance had been improved so obviously that 93.9% of the initial capacity were preserved after 100 cycles. Furthermore, electrochemical impedance tests were carried out with the spinel Lil. o2Coo. ozCro. olLao. Mn196Fo. o203. 98 as working electrode, Lithium as counter elec- trode and reference electrode. Results showed that this material possessed good charge/discharge reversible capa- bility and had the lowest impedance in 3. 95-4. 25 V range (on the stage of charge/discharge).

采用固相反应法在惰性气氛中合成了橄榄石型LiFePO/C复合正极材料，考察了焙烧温度对目标材料性能的影响，采用XRD、SEM、TG-DSC、激光粒度分布以及电化学测试等手段对该材料进行了结构表征和性能测试。结果表明，完美的结晶、较小的粒径以及与导电剂的良好接触是产物具有优良电化学性能的保证。于750℃下制得产物的结构完整，表面形貌较好，粒经分布均匀，具有良好的电化学性能。在室温及0.05C充放电倍率下，该材料的首次放电容量为142.5mA•h/g，循环50次后，未见明显衰减。

采用高温固相法合成了掺杂改性的锂离子电池用尖晶石型LiMn2-X-Y CoxLay CO4-XLaO4-C1/C和复合型LiMn2-X-Y CoxLay CO4-XLaO4-C1/C正极材料，通过X射线衍射和环境扫描电镜对材料的晶体结构和表观形貌进行了分析，通过恒电流充放电测试和交流阻抗技术对材料的电化学性能进行了测试。实验结果表明，所制备的材料LiMn2-X-Y CoxLay CO4-XLaO4-C1/C和LiMn2-X-Y CoxLay CO4-XLaO4-C1/C均为单一的尖晶石结构，其中以葡萄糖作为碳添加剂所得的复合材料的电性能最佳。该材料具有良好的充放电循环可逆性能，以0.2C倍率充放电，首次放电比容量可达126.5mAh•g，充放电循环50次后平均放电比容量仍保持在123.5mAh•g以上，衰减不超过2.4%。

安全性是高容量及动力型锂离子电池商品化的主要障碍。当在热冲击、过充、过放、短路等滥用状态下，电池内部的活性物质及电解液等组分间将发生化学、电化学反应，产生大量的热量与气体，当积累到一定程度就会引起电池的着火、爆炸。本文综述了电池内部热量的来源和产生的原因，分析了电池在加热、过充、短路等状态下的爆炸机理，并提出了解决电池爆炸问题的具体措施。

采用高温固相法合成了复合离子掺杂的尖晶石型锰酸锂Li1.02CrCoLacMnz a b cd F2O4-Y（a， b，c=0，0.01，0.02；y=0，0.02）正极材料。XRD表征合成物均具有良好的尖晶石型结构。充放电表明多元复合掺杂产物Li1.02Cr0.02La0.01Mn1.96F0.02O3.98，作为锂离子电池正极材料较未掺杂或仅掺杂阳离子的材料能够更好地抑制可逆容量在充放电循环中的衰减，80次循环充放电比容量（120.1～113.5mAh•g）仍保持94.5%以上。高温（55℃）循环性能也有较大的改善。交流阻抗测试结果表明该材料在充放电平台附近有较小的阻抗和良好的充放电可逆性。