采用共沉淀-高温固相法制备LiNi_(0.6)Co_(0.1)Mn_(0.3)O_2锂离子正极材料,并使用X射线衍射仪(XRD)和扫描电镜(SEM)技术分别表征其结构和形貌.然后将所得LiNi_(0.6)Co_(0.1)Mn_(0.3)O_2正极材料组装成扣式电池,并表征其电化学性能,探讨...采用共沉淀-高温固相法制备LiNi_(0.6)Co_(0.1)Mn_(0.3)O_2锂离子正极材料,并使用X射线衍射仪(XRD)和扫描电镜(SEM)技术分别表征其结构和形貌.然后将所得LiNi_(0.6)Co_(0.1)Mn_(0.3)O_2正极材料组装成扣式电池,并表征其电化学性能,探讨烧结温度和锂配量对其电化学性能的影响.结果表明:所得LiNi_(0.6)Co_(0.1)Mn_(0.3)O_2正极材料的放电比容量随烧结温度的升高而增大,且在900℃时表现出最佳的电化学性能.室温下,1C倍率下,锂配量(n(Li)/n(Ni+Co+Mn)=1.09)时,正极材料的首次放电容量为143.7 m Ah/g,50次循环后,正极材料的放电比容量仍有141.3 m Ah/g,容量保持率为98.3%.展开更多
LiNi0.8Co0.1Mn0.1O2 powder was prepared by mixing LiOH·H2O and co-precipitated Ni0.8Co0.1Mn0.1（OH）2 at a molar ratio of 1：1.05, followed by sintering at different temperatures. The effects of temperature on th...LiNi0.8Co0.1Mn0.1O2 powder was prepared by mixing LiOH·H2O and co-precipitated Ni0.8Co0.1Mn0.1（OH）2 at a molar ratio of 1：1.05, followed by sintering at different temperatures. The effects of temperature on the morphology, structure and electrochemical performance were extensively studied. SEM and XRD results demonstrate that the sintering temperature has large influence on the morphology and structure and suitable temperature is very important to obtain spherical materials and suppresses the ionic distribution. The charge-discharge tests show that the electrochemical performance of LiNi0.8Co0.1Mn0.1O2 powders becomes better with the increase of temperature from 700 ℃ to 750 ℃ and higher temperature will deteriorate the performance. Although both of materials obtained at 750 ℃ and 780 ℃ demonstrate almost identical cyclic stability at 2C rate, which delivers 71.9%retention after 200 cycles, the rate performance of powder calcined at 780 ℃ is much poorer than that at 750 ℃. The XRD results demonstrate that the poor performance is ascribed to more severe ionic distribution caused by higher temperature.展开更多
采用共沉淀-高温固相法制备出Ni-Mn固溶的LiNi_(0.9)Mn_(0.1)O_2正极材料,并对材料进行ZrO_2掺杂改性,提高其性能。结合X-射线衍射(XRD)、扫描电镜(SEM)、电化学性能测试分析对LiNi_(0.9)Mn_(0.1)O_2材料性能进行表征。研究表明:掺杂能...采用共沉淀-高温固相法制备出Ni-Mn固溶的LiNi_(0.9)Mn_(0.1)O_2正极材料,并对材料进行ZrO_2掺杂改性,提高其性能。结合X-射线衍射(XRD)、扫描电镜(SEM)、电化学性能测试分析对LiNi_(0.9)Mn_(0.1)O_2材料性能进行表征。研究表明:掺杂能改善材料的电化学性能,ZrO_2掺杂量为1.5%,在25℃、2.75～4.35 V下,材料的首次放电比容量为199.8 m Ah/g,循环50次后,容量保持率为89.79%,在-20℃低温下,放电效率为71.68%。同时分析了材料内阻随放电深度的变化,确定材料电化学阻抗值的变化规律。展开更多
采用共沉淀高温固相反应法合成锂离子电池正极材料LiNi_(0.8)Co_(0.1)Mn_(0.1)O_2(811),通过掺入Li、Mg和Al元素,并采用SEM、XRD、电化学测试,研究掺杂对材料晶体结构和电化学性能影响规律.实验结果表明:共沉淀过程中三价金属离子(Mn^(...采用共沉淀高温固相反应法合成锂离子电池正极材料LiNi_(0.8)Co_(0.1)Mn_(0.1)O_2(811),通过掺入Li、Mg和Al元素,并采用SEM、XRD、电化学测试,研究掺杂对材料晶体结构和电化学性能影响规律.实验结果表明:共沉淀过程中三价金属离子(Mn^(3+)、Al^(3+))出现会促使少量α-Ni(OH)2形成,而Li^+、Mg^(2+)和Al^(3+)均溶入晶格无杂相析出.高温融锂反应中,三种掺杂元素显著削弱Ni^(2+)出现数量,抑制Ni^(2+)混排进入Li^+格位,大幅提升811基体可逆容量;Mg^(2+)、Al^(3+)掺杂进一步增强基体晶格稳定性,改善其循环性能;Li^+-Al^(3+)共掺杂使之达到最佳:首次充电效率ICE超过90%,0.2C倍率下50次循环容量达195.8 m Ah/g、容量保持率为96.2%.展开更多
文摘采用共沉淀-高温固相法制备LiNi_(0.6)Co_(0.1)Mn_(0.3)O_2锂离子正极材料,并使用X射线衍射仪(XRD)和扫描电镜(SEM)技术分别表征其结构和形貌.然后将所得LiNi_(0.6)Co_(0.1)Mn_(0.3)O_2正极材料组装成扣式电池,并表征其电化学性能,探讨烧结温度和锂配量对其电化学性能的影响.结果表明:所得LiNi_(0.6)Co_(0.1)Mn_(0.3)O_2正极材料的放电比容量随烧结温度的升高而增大,且在900℃时表现出最佳的电化学性能.室温下,1C倍率下,锂配量(n(Li)/n(Ni+Co+Mn)=1.09)时,正极材料的首次放电容量为143.7 m Ah/g,50次循环后,正极材料的放电比容量仍有141.3 m Ah/g,容量保持率为98.3%.
基金Project(2014CB643406)supported by the National Basic Research Program of China
文摘LiNi0.8Co0.1Mn0.1O2 powder was prepared by mixing LiOH·H2O and co-precipitated Ni0.8Co0.1Mn0.1（OH）2 at a molar ratio of 1：1.05, followed by sintering at different temperatures. The effects of temperature on the morphology, structure and electrochemical performance were extensively studied. SEM and XRD results demonstrate that the sintering temperature has large influence on the morphology and structure and suitable temperature is very important to obtain spherical materials and suppresses the ionic distribution. The charge-discharge tests show that the electrochemical performance of LiNi0.8Co0.1Mn0.1O2 powders becomes better with the increase of temperature from 700 ℃ to 750 ℃ and higher temperature will deteriorate the performance. Although both of materials obtained at 750 ℃ and 780 ℃ demonstrate almost identical cyclic stability at 2C rate, which delivers 71.9%retention after 200 cycles, the rate performance of powder calcined at 780 ℃ is much poorer than that at 750 ℃. The XRD results demonstrate that the poor performance is ascribed to more severe ionic distribution caused by higher temperature.
文摘采用共沉淀-高温固相法制备出Ni-Mn固溶的LiNi_(0.9)Mn_(0.1)O_2正极材料,并对材料进行ZrO_2掺杂改性,提高其性能。结合X-射线衍射(XRD)、扫描电镜(SEM)、电化学性能测试分析对LiNi_(0.9)Mn_(0.1)O_2材料性能进行表征。研究表明:掺杂能改善材料的电化学性能,ZrO_2掺杂量为1.5%,在25℃、2.75～4.35 V下,材料的首次放电比容量为199.8 m Ah/g,循环50次后,容量保持率为89.79%,在-20℃低温下,放电效率为71.68%。同时分析了材料内阻随放电深度的变化,确定材料电化学阻抗值的变化规律。
文摘采用共沉淀高温固相反应法合成锂离子电池正极材料LiNi_(0.8)Co_(0.1)Mn_(0.1)O_2(811),通过掺入Li、Mg和Al元素,并采用SEM、XRD、电化学测试,研究掺杂对材料晶体结构和电化学性能影响规律.实验结果表明:共沉淀过程中三价金属离子(Mn^(3+)、Al^(3+))出现会促使少量α-Ni(OH)2形成,而Li^+、Mg^(2+)和Al^(3+)均溶入晶格无杂相析出.高温融锂反应中,三种掺杂元素显著削弱Ni^(2+)出现数量,抑制Ni^(2+)混排进入Li^+格位,大幅提升811基体可逆容量;Mg^(2+)、Al^(3+)掺杂进一步增强基体晶格稳定性,改善其循环性能;Li^+-Al^(3+)共掺杂使之达到最佳:首次充电效率ICE超过90%,0.2C倍率下50次循环容量达195.8 m Ah/g、容量保持率为96.2%.
