LiNi_(0.5)Mn_(1.5)O_4(LNMO) was prepared by a high-temperature solid phase method,and then Al PO_(4)(AP) was coated on the polyhedral LNMO surface by the wet chemical method.The experimental results showed that the LN...LiNi_(0.5)Mn_(1.5)O_4(LNMO) was prepared by a high-temperature solid phase method,and then Al PO_(4)(AP) was coated on the polyhedral LNMO surface by the wet chemical method.The experimental results showed that the LNMO-1%AP|Li cell prepared with a 1%mass ratio of Al PO_(4and) LNMO had better electrochemical performance;after 450 cycles at 1C,its discharge specific capacity maintained 108.78 m Ah·g^(-1),while that of the LNMO|Li cell was only 86.04 m Ah·g^(-1).Especially at the high rates of 5C and 10C,the electrochemical properties of the former were far superior to the latter.This was attributed to the fact that the AP coating made the surface of LNMO in contact with the electrolyte more stable,effectively promoted the Li~+transport,and reduced the polarization voltage of the electrode.展开更多
通过酚醛树酯包覆和碳热反应在富锂正极材料表面原位构建碳和尖晶石双壳保护结构,对这种核壳结构的正极材料进行了结构和形貌表征,并研究了其电化学性能.研究发现,尖晶石相为材料提供了三维锂离子迁移通道,碳包覆层显著提高了正极材料...通过酚醛树酯包覆和碳热反应在富锂正极材料表面原位构建碳和尖晶石双壳保护结构,对这种核壳结构的正极材料进行了结构和形貌表征,并研究了其电化学性能.研究发现,尖晶石相为材料提供了三维锂离子迁移通道,碳包覆层显著提高了正极材料的电子电导率,两种效应的共同作用极大降低了材料的电化学阻抗,提升了材料的放电比容量,这种多壳层结构正极材料还具有优异的倍率性能,在5C倍率下放电比容量可达到135.1 m A·h/g.展开更多
本文以商用氟化石墨为原料,通过水合肼还原的方法对氟化石墨(CFx)进行改性处理,系统研究了不同水合肼用量对材料电化学性能的影响.采用XRD、SEM、EDS、XPS、交流阻抗(EIS)和恒流放电测试技术,对改性氟化石墨材料的物相及电化学性能进行...本文以商用氟化石墨为原料,通过水合肼还原的方法对氟化石墨(CFx)进行改性处理,系统研究了不同水合肼用量对材料电化学性能的影响.采用XRD、SEM、EDS、XPS、交流阻抗(EIS)和恒流放电测试技术,对改性氟化石墨材料的物相及电化学性能进行了分析研究.结果表明,采用改性氟化石墨材料制备的锂/氟化碳(Li/CFx)电池的电压滞后现象得到明显改善,且不同水合肼用量对材料的电化学性能有重要影响.H-CFx-2(CFx:C2H6O:N2H4·H2O的比例为1:2:1)材料的综合性能最佳,在0.1C倍率下,材料的克比容量达到794.5 m Ah·g-1,平台电压为2.53V,电压滞后现象的低波电压为2.37 V.展开更多
文摘LiNi_(0.5)Mn_(1.5)O_4(LNMO) was prepared by a high-temperature solid phase method,and then Al PO_(4)(AP) was coated on the polyhedral LNMO surface by the wet chemical method.The experimental results showed that the LNMO-1%AP|Li cell prepared with a 1%mass ratio of Al PO_(4and) LNMO had better electrochemical performance;after 450 cycles at 1C,its discharge specific capacity maintained 108.78 m Ah·g^(-1),while that of the LNMO|Li cell was only 86.04 m Ah·g^(-1).Especially at the high rates of 5C and 10C,the electrochemical properties of the former were far superior to the latter.This was attributed to the fact that the AP coating made the surface of LNMO in contact with the electrolyte more stable,effectively promoted the Li~+transport,and reduced the polarization voltage of the electrode.
文摘通过酚醛树酯包覆和碳热反应在富锂正极材料表面原位构建碳和尖晶石双壳保护结构,对这种核壳结构的正极材料进行了结构和形貌表征,并研究了其电化学性能.研究发现,尖晶石相为材料提供了三维锂离子迁移通道,碳包覆层显著提高了正极材料的电子电导率,两种效应的共同作用极大降低了材料的电化学阻抗,提升了材料的放电比容量,这种多壳层结构正极材料还具有优异的倍率性能,在5C倍率下放电比容量可达到135.1 m A·h/g.
文摘本文以商用氟化石墨为原料,通过水合肼还原的方法对氟化石墨(CFx)进行改性处理,系统研究了不同水合肼用量对材料电化学性能的影响.采用XRD、SEM、EDS、XPS、交流阻抗(EIS)和恒流放电测试技术,对改性氟化石墨材料的物相及电化学性能进行了分析研究.结果表明,采用改性氟化石墨材料制备的锂/氟化碳(Li/CFx)电池的电压滞后现象得到明显改善,且不同水合肼用量对材料的电化学性能有重要影响.H-CFx-2(CFx:C2H6O:N2H4·H2O的比例为1:2:1)材料的综合性能最佳,在0.1C倍率下,材料的克比容量达到794.5 m Ah·g-1,平台电压为2.53V,电压滞后现象的低波电压为2.37 V.
