Electrochemical properties of LaFeO3-rGO composite

LaFeO_3-xwt% r GO composite(x = 8, 10, 12) was synthesized by ultraphonic stirring and lyophilization method.SEM, TEM and XRD results show that the perovskite-type LaFeO_3 was dispersed by rGO to form special porous structure due to the gauze-shaped wrinkles and folds structure of rGO. It was found that the special porous structure can effectively increase the specific surface area and suppress particle aggregation of LaFeO_3, thus improving the electrical conductivity and appreciably enhancing the electrochemical properties of LaFeO_3. As compared with LaFeO_3, the maximum discharge capacity of the composite(x=10) increased from 209.5 mAhg~(–1) to 334.6 mAhg~(–1).The High rate dischargeability at a discharge current density of 1500 mAg~(–1)(HRD1500) and the capacity retention rate after 100 charge/discharge cycles(S100) of the composite increased by 9% and 17%, respectively.     

纯电动车用18650电池的一致性研究

通过对国内外五款纯电动车用18650电池进行电化学性能测试、变异系数分析和相关性分析,评估电池在初始阶段和老化过程中的一致性,并系统分析电流、温度及电压范围对电池一致性的影响.结果表明:为了提高纯电动车用18650电池全寿命周期内的一致性,必须控制充电倍率小于0.3C,放电倍率小于0.5C,使用温度高于0℃.此外,优化电池筛选工艺也是改善电池一致性的一个重要方法.初始筛选时加入能够表征寿命因素的特征参数k值,即静置时开路电压的下降速率,是非常有效的.     

高能量密度锂离子电池层状锰基正极材料研究进展

层状锰基材料Li[Lix(MnM)1-x]O2(M=Ni,Co,Cr,…)以高比容量成为最具应用前景的正极体系之一,近年来成为研究热点而倍受关注,尤其借助原位测试分析等先进表征手段,对Li[Lix(MnM)1-x]O2的结构及其高容量获取机理的研究取得显著进展.本文概括介绍了高能量密度层状正极材料的结构与充放电机理,重点针对其目前依然存在的问题,详细归纳了Li[Lix(MnM)1-x]O2正极材料充放电循环过程中电压衰减机理、界面/表面特征以及性能改善的研究新进展,而且对高能量密度层状正极材料的未来研究方向也进行了探讨.     

Aromatic carbon coated tin composites as anode materials for lithium ion batteries

Aromatic carbon coated tin composites (A/Sn) have been prepared by thermal decomposition of the stannous 1,8-naphthalenedicarboxylate precursors, which is a reformative preparation method. Sugar carbon coated tin composites (S/Sn) also are prepared as a contrast with the A/Sn composites. The morphology and composition of the products were characterized by Scanning Electricity Microscopy (SEM) and X-Ray Diffraction (XRD). Their electrochemical performance as anode materials for lithium ion batteries were investigated; the results indicated that these materials exhibited good performance, and the cycle stability of A/Sn composites is especially superior to the S/Sn composites due to its special carbon resource.     

高倍率镉镍电池镉负极的改进

通过对镉负极进行表达处理，研制出具有优良的高倍率充放电性能的镉镍电池，寿命试验按国际（ＧＢ１０１７－８９）要求进行５００次测试，仍有８５％以上的剩余容量。     

溶胶凝胶法制备纳米级锂离子电池正极材料LiCrxMn2-xO4

通过溶胶凝胶法低温下合成了 Cr与 Mn不同计量比的一系列正极材料 Li Crx Mn2 -x O4 ,并用 DTA,TGA,TEM,XRD,FT- IR对其形貌及其结构进行了表征 .结果表明采用该方法在4 5 0℃的低温下即可得到纯相的 L i Crx Mn2 -x O4 尖晶石 ,其平均粒径均为 80 nm左右 ,且分布均匀     

固体高铁酸钡热分解动力学的研究

文中对固体高铁酸钡在不同温度下进行了稳定性研究。热分解是导致该物质稳定性较差的重要因素。该过程为一级反应 ,反应活化能力为 38.8kJ/mol,频率因子为 6.0 7× 1 0 - 5。     

无粘结剂V2O5纳米线/CNT电极的制备及电化学性能

把羧化的碳纳米管与水热法合成的V2O5纳米线混合超声处理后,直接真空抽滤得到无粘结剂V2O5纳米线/CNT纸.对加入不同含量的碳纳米管的样品,综合考虑比容量和循环性能,其中m（V2O5）∶m（CNT）=1∶1样品的电化学性能最好.当电流密度为30 mA·g-1时,首次放电比容量能达到290.6 mAh·g-1,接近于V2O5的理论比容量,10次循环以后为265.4mAh·g-1,容量保持率为91.32％.当电流密度为600 mA·g-1,首次放电比容量71.2 mAh·g-1,第10次循环为62.5 mA·g-1,容量保持率可达87.8％.     

Three-dimensionally macroporous graphene-supported Fe3O4 composite as anode material for Li-ion batteries with long cycling life and ultrahigh rate capability

Fe3O4 is an attractive conversion reaction- based anode material with high theoretical capacity （928 mA h g^-1）. However, the poor cycling and rate per- formance hinder its applications in Li-ion batteries. In this work, we report an effective strategy to synthesize three- dimensionally macroporous graphene-supported Fe3O4 hybrid composite. Benefiting from advantage of the special structure, the hybrid composite exhibits excellent Li^＋ stor- age performance, delivering a high reversible capacity of 980 mA h g^-1at the current density of 4 A g^-1 even after 470 cycles and ultrahigh rate capability （293 mA h g^- 1 even at current density of 20 A g^-1）.