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《钢铁钒钛》2021,42(3):94-98
采用自蔓延高温合成法制备了添加不同含量合金元素Al或Cr的新型钒基新能源汽车电池负极合金V65Ti20Ni15,并进行了显微组织、电化学循环稳定性和耐腐蚀性能的测试与分析。结果表明,合金元素Al或Cr,有助于改善合金内部组织,提高合金的电化学循环稳定性和耐腐蚀性能;复合添加合金元素Cr和Al的V59Ti20Ni15Al3Cr3合金的电化学循环稳定性和耐腐蚀性能最佳。与不添加合金元素的V65Ti20Ni15合金相比,复合添加合金元素Cr和Al的V59Ti20Ni15Al3Cr3合金的充放电循环50次后放电容量衰减率从85%减小到23%、腐蚀电位正移692 mV,合金的电化学循环稳定性和耐腐蚀性能得到显著提高。 相似文献
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为了降低贮氢合金中的钴含量,从而降低镍氢电池的价格,在贮氢合金M1Ni3.55Co0.75Al0.3Mn0.4的基础上,依次添加Cu、Cr、Zn、Fe元素,得到稀土基多元贮氢合金,并对其放电容量和循环稳定性进行了测试和分析。结果表明,适量的Cu、Cr、Zn、Fe替代Co,仍能使贮氢合金具有较高的放电容量和较好的循环稳定性。 相似文献
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掺Co3+和Li+的LiMn2O4晶体结构和电化学性能研究 总被引:4,自引:2,他引:4
以尖晶石LiMn2O4,Li2CO3和Co3O4为原料,采用固相烧结法合成了尖晶石锰酸锂的改性产物。X射线粉末衍射分析表叫,改性产物保持了LiMn2O4的立方尖晶石结构。采用Rietveld方法进行结构精修表明,掺杂元素进入了晶胞中的16d位置,改性产物结构分子式可写成[Li]s4[Mn2-x Lix/4Co3x/4]16a[O4]32e。随着钻和锂掺杂量的增加,产物16d位置中更多的锰被取代,锰离了平均价态逐渐升高,锰和氧的结合键能增加,键长下降,晶格参数减小。电性能测试表明,锰酸锂掺杂钴、锂后,循环稳定性提高,比容量稍有降低。当锂、钴掺杂量为锰酸锂的0.025倍时.综合性能最佳。 相似文献
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富锂锰基氧化物(LMO)正极材料具有很高的比容量,但其仍存在首次不可逆容量损失大、动力学性能差、电压衰降等缺陷.本文设计并优化Li1.2Ni0.13Co0.13Mn0.54O2正极材料结构,通过掺杂Br-取代O2-限制充放电循环过程晶格氧的迁移;通过调控富锂锰基氧化物电极中的氧空位,增强氧阴离子反应的可逆性,改善电极的... 相似文献
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铬对尖晶石锂锰氧化物电化学性质的影响 总被引:2,自引:0,他引:2
研究了纯尖晶石锂锰氧化物和掺铬尖晶石锂锰氧化物粉末微电极的循环伏安曲线和交流阻抗谱图,结果表明;掺铬样品循环稳定性明显增加,但它的氧化还原峰的位置发生正移,峰形宽化,两步嵌脱锂的量也由相等变为不等,反应电阻增加。 相似文献
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《中国锰业》2017,(1)
对水热法合成的无定形Li-Mn-Me-O前驱体(Me=0、Co或Co-Ti)进行热处理,制备了Co掺杂及Co-Ti复合掺杂的尖晶石型LiMn_2O_4正极材料。通过XRD、SEM对Co-Ti复合掺杂的LiMn_2O_4的结构和微观形貌进行分析与表征,并测试了其电化学性能。研究结果表明:所制备的粉体材料具有良好的立方尖晶石结构,无杂相峰存在;Co-Ti复合掺杂使LiMn_2O_4颗粒变小;其在3.0~4.3 V电压范围内,0.5C倍率条件下,首次放电比容量为116.5 m Ah/g,循环100圈后容量保持率为93.5%;与不掺杂样品相比,其初始容量提高,100次循环的容量保持率提高,且高倍率循环性能也明显得到改善。 相似文献
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为改善尖晶石LiMn2O4的循环性能,采用高温固相法合成了由Li2CO3改性的尖晶石锂锰氧化物,研究了Li2CO3添加量对LiMn2O4性能的影响。通过XRD,Rietveld精细XRD分析和模拟电池等方法对产物的结构和电化学性能进行了表征与测试。结果表明,部分Li进入到尖晶石LiMn2O4的晶格中,增强了材料充放电循环过程中的结构稳定性。随着Li2CO3量的增加,产物的循环稳定性增加。当Li2CO3的加入量为0.06摩尔比时,10次循环后的高温容量衰减由改性前的15%降低到6.8%。 相似文献
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Sc3 -doped lithium manganese oxides were synthesized by solid-state reaction. The influences of doping element on structure,mean valence of manganese, and electrochemical performances were studied by X-ray diffraction (XRD), galvanostatic charge-discharge and cyclic voltammetric tests, and also electrochemical impedance spectroscopy (EIS). XRD tests showed that doped lithium manganese oxides were pure spinel structure without other phases. Redox titration and visible spectrophotometry tests indicated that the mean valence of man-ganese in doped lithium manganese oxides was higher than that of pure one. LiSc0.02Mn1.98O4 remained 92.9% of the initial specific discharge capacity after 50th cycle at a constant current of 50 m/g, and the reversibility of LiSc0.02Mn1.98O4 was improved in comparison with pure LiMn2O4 at 50 ℃. EIS indicated that film deposition on spinel particles was suppressed because of Sc3 doping, and the charge transfer be-tween the surface film and spinel particles with increasing temperature for Sc3 -doped materials became easier as compared with undoped one. 相似文献
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以KCl为熔盐,采用熔盐法合成了锂离子电池正极材料LiMn1/3Ni1/3Co1/3O2,扫描电子显微镜(SEM)显示此方法制备产物具有较好的晶形,颗粒较均匀.XRD表征结果显示产物为层状结构,充放电测试结果显示出材料在3.6 V平台附近有较大的可逆容量.在900℃时保温8 h时合成的LiMn1/3Ni1/3Co1/3O2具有较好的电化学性能,制作成AA电池,在2.75~4.2 V之间进行充放电测试,在1 C倍率下放电,LiMn1/3Ni1/3Co1/3O2的初始放电容量可达132.9 mAh/g,循环50多次后容量仍为124.6 mAh/g,容量保持率为93.75﹪. 相似文献
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The kinetic curve of the high-temperature oxidation of austenitic stainless steel Cr18Ni11Cu3Al3MnNb at different temperatures was measured by weighting method. It is showed that the oxidation curves at 700 and 800 ℃ followed the parabolic law, and the steel presented an excellent anti-oxidation. The surface morphology and structure of the oxide film were studied by scanning electron microscopy and X-ray diffraction methods. A dense oxide film was attained at 700 and 800 ℃, mainly composed of the hexagonal Al2O3, Fe2O3, and a small amount oxide of Cr at 700 ℃. At 900 ℃ the oxide film started to delaminate, and was composed of (Cr,Fe)2O3 and the spinel CuCrMnO4 and Fe(Cr,Al)2O4. 相似文献
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Forthepasttenyears,thespinelLiMn2O4hasbeenstudiedextensivelyasapositiveelectrodematerialsforrechargeablelithiumandlithiumioncells,becausetheyarecheaper,lesstoxicandmoreeasilypreparedthanothercandidatesLiCoO2andLiNiO2.Unfortunately,itspracticalapplication… 相似文献
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Influence of Doping Rare Earth on Performance of Lithium Manganese Oxide Spinels as Cathode Materials for Lithium-Ion Batteries 总被引:4,自引:0,他引:4
The cathode material plays an important role inthe performance of lithium ion batteries. Commerciallithium cells use lithium cobalt oxide cathodes and thehigh cost of this material has prompted the design andsynthesis of alternate insertion hosts. Among these al ternatives, spinel LiMn2O4 has been found to bepromising in terms of specific energy, non toxicity,and low cost[1~3]. It is thought that lithium man ganese oxides will be used in lithium ion batteries forel… 相似文献
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掺杂对锂离子筛吸附性能的影响 总被引:1,自引:0,他引:1
对Li/Mn为0.7的离子筛分别进行了铜钴镍的掺杂,XRD检测和化学分析表明掺杂元素进入了离子筛的晶格;掺入铜钴镍后离子筛中锰的溶损率分别降低了2%、1.3%、1.2%;饱和吸附容量随掺入元素量的增加逐渐变小,当掺入铜钴镍的量由0增加到0.15时,饱和吸附容量由27.6 mg/g分别下降到7.8 mg/g、13.3 mg/g、18.3 mg/g。铜钴镍在离子筛中能降低锰的溶损率,但同时也降低了饱和吸附容量。 相似文献