As a potential substitute for LiFePO4, LiMnPO4 has attracted more and more attention due to its higher energy, showing potential application in electric vehicle（EV） or hybrid electric vehicle（HEV）. In this work,so...As a potential substitute for LiFePO4, LiMnPO4 has attracted more and more attention due to its higher energy, showing potential application in electric vehicle（EV） or hybrid electric vehicle（HEV）. In this work,solvothermal method was used to prepare nano-sized LiMnPO4, where ethylene glycol was used as solvent, and lithium acetate（LiAc）, phosphoric acid（H3 PO4） and manganese chloride（MnCl2） were used as precursors. The crystal structure and morphology of the obtained products were characterized by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The electrochemical performance was evaluated by charge-discharge cycling, cyclic voltammetry and electrochemical impedance spectroscopy. The results show that the molar ratio of LiAc：H3 PO4：MnCl2 plays a critical role in directing the morphology of LiMnPO4. Large plates transform into irregular nanoparticles when the molar ratio changes from 2：1：1 to 6：1：1. After carbon coating, the product prepared from the 6：1：1 precursor could deliver discharge capacities of 156.9,122.8, and 89.7 mAhg-1 at 0.05 C, 1 C and 10 C, respectively.The capacity retention can be maintained at 85.1% after 200 cycles at 1 C rate for this product.展开更多
采用以离子液体乙醇胺乳酸盐为反应介质的离子热法在常压低温下成功制备出LiMnPO4,经添加蔗糖后在不同温度下高温处理获得了LiMnPO4/C正极材料。通过X射线衍射、扫描电子显微镜和透射电子显微镜表征了材料的相态和形貌,采用充放电法研...采用以离子液体乙醇胺乳酸盐为反应介质的离子热法在常压低温下成功制备出LiMnPO4,经添加蔗糖后在不同温度下高温处理获得了LiMnPO4/C正极材料。通过X射线衍射、扫描电子显微镜和透射电子显微镜表征了材料的相态和形貌,采用充放电法研究了材料的电化学性能。结果表明:磷酸锰锂的晶相为橄榄石型;材料颗粒的尺寸主要分布在150～300 nm;较高温度下获得的LiMnPO4/C材料表现出较好的电化学性能,在0.05 C下放电容量达114.0 mA h/g,10次循环后比容量仍保持在102.3 mA h/g。这种以乙醇胺乳酸盐为反应介质的离子热法为锂离子电池正极材料LiMnPO4的制备提供了新的途径。展开更多
在采用溶剂热法制备磷酸锰锂的基础上,以蔗糖和石墨烯为碳源,制备了裂解碳和石墨烯含量不同的磷酸锰锂/碳/石墨烯复合材料,研究了裂解碳和石墨烯对材料性能的影响。采用扫描电镜(SEM)和透射电镜(TEM)对材料的形貌进行了表征。裂解碳包...在采用溶剂热法制备磷酸锰锂的基础上,以蔗糖和石墨烯为碳源,制备了裂解碳和石墨烯含量不同的磷酸锰锂/碳/石墨烯复合材料,研究了裂解碳和石墨烯对材料性能的影响。采用扫描电镜(SEM)和透射电镜(TEM)对材料的形貌进行了表征。裂解碳包覆可以提高LiMnPO_4纳米片表面的电子导电性,对于材料性能的改善起到主要的作用;石墨烯可以提高纳米片之间的电子和离子导电性,改善材料的电化学性能。电化学测试表明,当裂解碳含量为4%、石墨烯含量为2%时,LiMnPO_4电极具有较好的电化学性能,在0.5C下的放电比容量为139.1 m Ah·g-1,循环100次后,容量保持率为93.6%。与添加单一碳和单一石墨烯的LiMnPO_4电极相比,该电极在0.5C下的放电比容量分别提高了35.0%和48.6%。展开更多
采用水热法和湿磨结合的方法合成了碳包覆的LiMnPO_4和Co_3O_4与碳混合包覆的LiMnPO_4。测试结果表明Co_3O_4与碳形成的完整混合包覆层不仅能抑制LiMnPO_4再次团聚,而且能更有效地保护LiMnPO_4免受电解液的侵蚀,降低电荷转移电阻。Co_3O...采用水热法和湿磨结合的方法合成了碳包覆的LiMnPO_4和Co_3O_4与碳混合包覆的LiMnPO_4。测试结果表明Co_3O_4与碳形成的完整混合包覆层不仅能抑制LiMnPO_4再次团聚,而且能更有效地保护LiMnPO_4免受电解液的侵蚀,降低电荷转移电阻。Co_3O_4-LiMnPO_4/C在0.1 C的首次放电比容量为148.5 m Ah/g,在0.1 C循环50次后,容量保持率为94.6%,而LiMnPO_4/C仅为92.2%。此外,Co_3O_4-LiMnPO_4/C也表现出突出的高倍率性能,在6 C,8 C和10 C下的放电比容量为101.4,89.5和85 m Ah/g。展开更多
基金supported financially by the National Natural Science Foundation of China (No. 51572238)the Strategic Emerging Industry Project of Hunan Province, China (No. 2016GK4030)
文摘As a potential substitute for LiFePO4, LiMnPO4 has attracted more and more attention due to its higher energy, showing potential application in electric vehicle（EV） or hybrid electric vehicle（HEV）. In this work,solvothermal method was used to prepare nano-sized LiMnPO4, where ethylene glycol was used as solvent, and lithium acetate（LiAc）, phosphoric acid（H3 PO4） and manganese chloride（MnCl2） were used as precursors. The crystal structure and morphology of the obtained products were characterized by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The electrochemical performance was evaluated by charge-discharge cycling, cyclic voltammetry and electrochemical impedance spectroscopy. The results show that the molar ratio of LiAc：H3 PO4：MnCl2 plays a critical role in directing the morphology of LiMnPO4. Large plates transform into irregular nanoparticles when the molar ratio changes from 2：1：1 to 6：1：1. After carbon coating, the product prepared from the 6：1：1 precursor could deliver discharge capacities of 156.9,122.8, and 89.7 mAhg-1 at 0.05 C, 1 C and 10 C, respectively.The capacity retention can be maintained at 85.1% after 200 cycles at 1 C rate for this product.
文摘采用以离子液体乙醇胺乳酸盐为反应介质的离子热法在常压低温下成功制备出LiMnPO4,经添加蔗糖后在不同温度下高温处理获得了LiMnPO4/C正极材料。通过X射线衍射、扫描电子显微镜和透射电子显微镜表征了材料的相态和形貌,采用充放电法研究了材料的电化学性能。结果表明:磷酸锰锂的晶相为橄榄石型;材料颗粒的尺寸主要分布在150～300 nm;较高温度下获得的LiMnPO4/C材料表现出较好的电化学性能,在0.05 C下放电容量达114.0 mA h/g,10次循环后比容量仍保持在102.3 mA h/g。这种以乙醇胺乳酸盐为反应介质的离子热法为锂离子电池正极材料LiMnPO4的制备提供了新的途径。
文摘以单分散法制备的聚甲基丙烯酸甲酯(PMMA)微球为模板,合成三维多孔(3DOM)LiMnPO_4锂电池正极材料,制备的材料为橄榄石型结构。N_2吸附-脱附分析显示,3DOM LiMnPO_4比表面积较大,为34.63 m^2/g。电化学性能测试表明,首次比容量接近于120 m A·h/g,循环充放电60次时仍保持较好的稳定性。模板法获得的LiMnPO_4呈多孔结构,有利于降低离子或电荷迁移到电解液或电极表面的阻力,从而降低了电极表面的极化,有利于锂离子脱嵌,进而提高充放电的循环稳定性。
文摘在采用溶剂热法制备磷酸锰锂的基础上,以蔗糖和石墨烯为碳源,制备了裂解碳和石墨烯含量不同的磷酸锰锂/碳/石墨烯复合材料,研究了裂解碳和石墨烯对材料性能的影响。采用扫描电镜(SEM)和透射电镜(TEM)对材料的形貌进行了表征。裂解碳包覆可以提高LiMnPO_4纳米片表面的电子导电性,对于材料性能的改善起到主要的作用;石墨烯可以提高纳米片之间的电子和离子导电性,改善材料的电化学性能。电化学测试表明,当裂解碳含量为4%、石墨烯含量为2%时,LiMnPO_4电极具有较好的电化学性能,在0.5C下的放电比容量为139.1 m Ah·g-1,循环100次后,容量保持率为93.6%。与添加单一碳和单一石墨烯的LiMnPO_4电极相比,该电极在0.5C下的放电比容量分别提高了35.0%和48.6%。
文摘采用水热法和湿磨结合的方法合成了碳包覆的LiMnPO_4和Co_3O_4与碳混合包覆的LiMnPO_4。测试结果表明Co_3O_4与碳形成的完整混合包覆层不仅能抑制LiMnPO_4再次团聚,而且能更有效地保护LiMnPO_4免受电解液的侵蚀,降低电荷转移电阻。Co_3O_4-LiMnPO_4/C在0.1 C的首次放电比容量为148.5 m Ah/g,在0.1 C循环50次后,容量保持率为94.6%,而LiMnPO_4/C仅为92.2%。此外,Co_3O_4-LiMnPO_4/C也表现出突出的高倍率性能,在6 C,8 C和10 C下的放电比容量为101.4,89.5和85 m Ah/g。
