将共沉淀法和固相法相结合,将Si 4+掺杂到LiNi 0.5 Mn 0.5 O 2中,合成LiNi 0.5-x Si x Mn 0.5 O 2(0≤x≤0.08)正极材料。通过XRD及精修、等离子体发射光谱(ICP)、SEM和透射电子显微镜(TEM)等方法,对合成材料的结构、成分和形貌进行分析...将共沉淀法和固相法相结合,将Si 4+掺杂到LiNi 0.5 Mn 0.5 O 2中,合成LiNi 0.5-x Si x Mn 0.5 O 2(0≤x≤0.08)正极材料。通过XRD及精修、等离子体发射光谱(ICP)、SEM和透射电子显微镜(TEM)等方法,对合成材料的结构、成分和形貌进行分析。Si 4+掺杂不仅可降低材料的锂镍混排程度,还能增强结构稳定性,且不会改变材料的形貌。以40 mA/g(0.2 C)的电流在2.5~4.5 V充放电,LiNi 0.47 Si 0.03 Mn 0.5 O 2(x=0.03)正极材料具有最好的电化学性能,不仅比容量(149.25 mAh/g)较未掺杂材料(125.44 mAh/g)提高20%,而且容量保持率在120次循环后也提高了7.7%。Si 4+掺杂能降低材料的锂镍混排程度,有利于Li+的迁移;能提高材料的结构稳定性,抑制电压的下降并减轻极化。展开更多
Layered Li(Ni0.5Mn0.5)1-xMxO2 (M=Ti, Al; x=0, 0.02) cathode materials for lithium-ion batteries were synthesized by one step solid-state method using Ni(OH)2, MnCO3, Li2CO3, TiO2 and Al(OH)3 as starting materials. The...Layered Li(Ni0.5Mn0.5)1-xMxO2 (M=Ti, Al; x=0, 0.02) cathode materials for lithium-ion batteries were synthesized by one step solid-state method using Ni(OH)2, MnCO3, Li2CO3, TiO2 and Al(OH)3 as starting materials. The effect of Ti and Al doping on the structure and electrochemical performance of Li(Ni0.5Mn0.5)1-xMxO2 (M=Ti, Al; x=0, 0.02) has been investigated. LiNi0.5Mn0.5O2, Li(Ni0.5Mn0.5)0.98Ti0.02O2 and Li(Ni0.5Mn0.5)0.98Al0.02O2 delivered 149 mAh·g-1, 160 mAh·g-1, 164 mAh·g-1, respectively, at a current of 20 mA·g-1 between 2.5 V and 4.3 V at room temperature, and remained 86%, 91%, 91% of the initial discharge capacity respectively after 30 cycles. AC impedance studies show that Ti and Al doping in Li(Ni0.5Mn0.5)1-xMxO2 (M=Ti, Al; x=0, 0.02) decreased the resistance of charge transfer Rct of cathode materials.展开更多
通过溶胶-凝胶法合成正极材料LiNi0.5Mn0.5O2,为了提高材料LiNi0.5Mn0.5O2的高倍率放电性能,采用Mg进行掺杂。通过X射线衍射(XRD),扫描电镜(SEM),恒电流充放电对材料的结构和形貌及电化学性能进行了研究。结果表明少量Mg的掺杂未影响到L...通过溶胶-凝胶法合成正极材料LiNi0.5Mn0.5O2,为了提高材料LiNi0.5Mn0.5O2的高倍率放电性能,采用Mg进行掺杂。通过X射线衍射(XRD),扫描电镜(SEM),恒电流充放电对材料的结构和形貌及电化学性能进行了研究。结果表明少量Mg的掺杂未影响到LiNi0.5Mn0.5O2的晶体结构,但改善了其电化学性能,其中,当Mg的掺杂量为5%(摩尔分数)时,材料具有更好的电化学性能,4 C放电时,首次放电比容量达到118 m Ah/g,且循环性能良好。展开更多
文摘将共沉淀法和固相法相结合,将Si 4+掺杂到LiNi 0.5 Mn 0.5 O 2中,合成LiNi 0.5-x Si x Mn 0.5 O 2(0≤x≤0.08)正极材料。通过XRD及精修、等离子体发射光谱(ICP)、SEM和透射电子显微镜(TEM)等方法,对合成材料的结构、成分和形貌进行分析。Si 4+掺杂不仅可降低材料的锂镍混排程度,还能增强结构稳定性,且不会改变材料的形貌。以40 mA/g(0.2 C)的电流在2.5~4.5 V充放电,LiNi 0.47 Si 0.03 Mn 0.5 O 2(x=0.03)正极材料具有最好的电化学性能,不仅比容量(149.25 mAh/g)较未掺杂材料(125.44 mAh/g)提高20%,而且容量保持率在120次循环后也提高了7.7%。Si 4+掺杂能降低材料的锂镍混排程度,有利于Li+的迁移;能提高材料的结构稳定性,抑制电压的下降并减轻极化。
文摘Layered Li(Ni0.5Mn0.5)1-xMxO2 (M=Ti, Al; x=0, 0.02) cathode materials for lithium-ion batteries were synthesized by one step solid-state method using Ni(OH)2, MnCO3, Li2CO3, TiO2 and Al(OH)3 as starting materials. The effect of Ti and Al doping on the structure and electrochemical performance of Li(Ni0.5Mn0.5)1-xMxO2 (M=Ti, Al; x=0, 0.02) has been investigated. LiNi0.5Mn0.5O2, Li(Ni0.5Mn0.5)0.98Ti0.02O2 and Li(Ni0.5Mn0.5)0.98Al0.02O2 delivered 149 mAh·g-1, 160 mAh·g-1, 164 mAh·g-1, respectively, at a current of 20 mA·g-1 between 2.5 V and 4.3 V at room temperature, and remained 86%, 91%, 91% of the initial discharge capacity respectively after 30 cycles. AC impedance studies show that Ti and Al doping in Li(Ni0.5Mn0.5)1-xMxO2 (M=Ti, Al; x=0, 0.02) decreased the resistance of charge transfer Rct of cathode materials.
文摘通过溶胶-凝胶法合成正极材料LiNi0.5Mn0.5O2,为了提高材料LiNi0.5Mn0.5O2的高倍率放电性能,采用Mg进行掺杂。通过X射线衍射(XRD),扫描电镜(SEM),恒电流充放电对材料的结构和形貌及电化学性能进行了研究。结果表明少量Mg的掺杂未影响到LiNi0.5Mn0.5O2的晶体结构,但改善了其电化学性能,其中,当Mg的掺杂量为5%(摩尔分数)时,材料具有更好的电化学性能,4 C放电时,首次放电比容量达到118 m Ah/g,且循环性能良好。
