失效锂离子电池正极材料的再生及电化学性能

以废旧锂离子电池正极材料钴酸锂为原料,将锂与钴元素的比例进行适当调整后,采用高温固相合成制备出LiCoO2材料,并利用XRD、SEM、循环伏安等手段对不同煅烧温度下合成LiCoO2材料的晶相结构、表面形貌及电化学性能进行测试表征.结果表明,经850℃煅烧12h后的LiCoO2材料的性能较好,首次充电容量达143mA.h/g,放电比容量达126mA.h/g,循环30周之后仍保持92%的放电比容量,再生后的LiCoO2材料表现出良好的电化学性能.     

Enhanced low-temperature performance of slight Mn-substituted LiFePO<Subscript>4</Subscript>/C cathode for lithium ion batteries

Low temperature performance of LiFePO₄/C cathode was remarkably improved by slight Mn-substitution. Electrochemical measurements showed that about 95% of the discharge capacity of LiFe_0.98Mn_0.02PO₄/C cathode at 20°C was obtained at 0°C, compared to 85% of that of LiFePO₄/C cathode. The LiFe_0.98Mn_0.02PO₄/C sample also presented enhanced rate performance at −20°C with the discharge capacities of 124.4 mA h/g (0.1C), 99.8 mA h/g (1C), 80.7mAh/g (2C) and 70 mA h/g (5C), respectively, while pristine LiFePO₄/C only delivered capacities of 120.5 mA h/g (0.1C), 90.7 mA h/g (1C), 70.4 mA h/g (2C) and 52.2 mA h/g (5C). Cyclic voltammetry measurements demonstrated an obvious improvement of the lithium insertion-extraction process of the LiFePO₄/C cathode by slight Mn-substitution. The results of FSEM observation and electrical conductivity measurement indicated that slight Mn-substitution minimized the particle size of LiFe_0.98Mn_0.02PO₄/C and also obviously improved the electrical conductivity of the compound, thus obviously enhances the interface reaction process on the cathode.     

Al-Mg-Pb-Sn-Ga铝合金阳极材料组织对电化学性能的影响

研究了冷轧变形量为95%Al-Mg-Pb-Sn-Ga五元铝合金阳极板材不同温度退火处理后的织构和其在4 mol/L NaOH+10 g/L Na2 SnO3溶液中的静态析氢速率与电化学性能.结果表明:此五元铝合金阳极板材,随退火温度的升高、保温时间的延长,立方织构含量增多,在4 mol/L NaOH溶液中反应后,表面腐蚀空隙率增多、深度增加,阳极极化减弱;回复退火处理的五元铝合金板材,析氢速率降低,稳定工作电位负移;再结晶退火时,随退火温度的升高、时间的延长,稳定工作电位的负移程度减少,析氢速率稍有增大.AM0501铝合金阳极板材在250℃-10 h、300℃-3 h回复退火,其在4 mol/LNaOH+10 g/L Na2 SnO3溶液中,恒电流极化时,具有理想的低自腐蚀析氢速率,负的稳定工作电位等电化学综合性能.     

限域于三维多孔碳的超细纳米尺度Cu2Sb合金用于钠离子和钾离子电池负极

Ultrafine nano-scale Cu₂Sb alloy confined in a three-dimensional porous carbon was synthesized using NaCl template-assisted vacuum freeze-drying followed by high-temperature sintering and was evaluated as an anode for sodium-ion batteries (SIBs) and potassium-ion batteries (PIBs). The alloy exerts excellent cycling durability (the capacity can be maintained at 328.3 mA·h·g?1 after 100 cycles for SIBs and 260 mA·h·g?1 for PIBs) and rate capability (199 mA·h·g?1 at 5 A·g?1 for SIBs and 148 mA·h·g?1 at 5 A·g?1 for PIBs) because of the smooth electron transport path, fast Na/K ion diffusion rate, and restricted volume changes from the synergistic effect of three-dimensional porous carbon networks and the ultrafine bimetallic nanoalloy. This study provides an ingenious design route and a simple preparation method toward exploring a high-property electrode for K-ion and Na-ion batteries, and it also introduces broad application prospects for other electrochemical applications.     

铝掺杂对无钴正极LiNi0.90Mn0.10O2结构及电化学性能的影响

采用共沉淀法将质量分数3%的Al取代Mn掺入二元Ni0.90Mn0.10OH₂前驱体中,经高温固相烧结合成一种无Co高Ni三元正极LiNi0.90Mn0.07Al0.03O₂,并通过X射线衍射(X ray diffraction,XRD)、扫描电子显微镜(scanning electron microscope,SEM)、能量弥散射线谱(energy dispersive spectroscopy,EDS)等表征手段进行分析,探讨了Al3＋掺杂对材料结构及性能的影响。结果表明,引入Al3＋后,Ni0.90Mn0.07Al0.03OH₂一次颗粒明显变细,对应LiNi0.90Mn0.07Al0.03O₂结晶度明显提高。在25 ℃、3.0~4.3 V下充放电,掺杂材料的0.1C比容量为191.3 mAh/g,高于未掺杂材料的181.5 mAh/g;0.5C循环90次的容量保持率为92.0%,高于未掺杂材料的89.3%;高温45 ℃下循环容量保持率为90.7%,高于未掺杂材料的92.2%。材料性能的提升可归因于Al3＋掺杂使得材料结晶度升高,稳定性提升,Li＋传递势垒降低。     

固态锂电池聚合物电解质研究进展

聚合物作为一种固态电解质具有优良的力学和机械性能,它的性质很大程度上决定了固态锂电池的电化学性能。对部分近期比较热门的聚合物电解质的研究进展进行简要总结,将不同聚合物电解质的性能和优缺点进行比较和讨论,并且对聚合物电解质的研究发展进行展望。     

Li-intercalation in Silicon Anodes: A Challenging Route Towards 3D-Integrated All-solid-state Batteries

1 Results Micro-batteries are expected to become more and more important in numerous small-sized devices,like medical implantables,biosensors,hearing aids and autonomous network devices.Characteristic for these electronic applications is that they have to operate autonomously and reliably.Due to these requirements thin film power sources need to be rechargeable,mechanically stable for a long period of time and have a long cycle life.As the average energy consumption of these future devices will be rathe...     

密封铅酸蓄电池的研究

阐述了密封铅酸蓄电池中板栅合金，极板制和加酸量控制方法。试验电池重量的体积能量密度分别为３５－３７Ｗｈ／ｋｇ和９３－９９Ｗｈ／ｄｍ＾３。放电率从０．０５～２Ｃ范围内的Ｐｅｕｋｅｒｔ直线斜率为１．１２。用电阻１．５Ω短接电池２１天后可用正常充电方法恢复至初始容量８６％。贮存６个月后的电池容量仅损失１７％。在５０％ＤＯＤ情况下，电池循环寿命大于５００次。     

层状LiNi1/3Mn1/3CO1/3O2正极材料的合成

用碳酸盐同沉淀法合成了LiNi1/3Mn1/3Co1/3O2正极材料,采用XRD(X-RayDiffraction)、SEM(ScanningElectronMicroscope)、差分计时电位法和充放电循环等对材料的物理化学性质及电化学性能进行了测试分析。XRD分析表明在合成温度为800℃或更高时,所合成的产物均为α-NaFeO2型的层状结构,SEM分析表明在合成温度为800或850℃时,产物为微小晶粒团聚成的球形颗粒,合成温度为900℃以上时,产物颗粒发生破碎,形状不规则。950℃合成的LiNi1/3Mn1/3Co1/3O2材料在2·5~4·4V电位区间内,首次放电容量为162mAh·g-1,并具有良好的循环性能。随着充放电电压的升高,首次不可逆放电容量增大,循环稳定性减弱。在低温(800,850℃)下合成的LiNi1/3Mn1/3Co1/3O2材料与高温下(900,950℃)得到的材料性能有很大差别,这是由于在高温和低温下得到材料的结构差别所造成的。