Well-developed crystalline LiNi0.5Mn1.5O4 was prepared by solid-state reaction using Li2CO3, NiO and electrolytic MnO2 at high heating and cooling rate. X-ray diffraction (XRD) patterns and scanning electron microscop...Well-developed crystalline LiNi0.5Mn1.5O4 was prepared by solid-state reaction using Li2CO3, NiO and electrolytic MnO2 at high heating and cooling rate. X-ray diffraction (XRD) patterns and scanning electron microscopic (SEM) images showed that LiNi0.5Mn1.5O4 synthesized at 900 ℃ and 950 ℃ had cubic spinel structure with clearly defined shape. LiNi0.5Mn1.5O4 spinel phase decomposed at 1 000 ℃ accompanying with structural and morphological degradation. TG measurement revealed that the weight loss during heating process could be mostly gained in cooling process, and the upward tendency of weight loss during heating process decreased, while that of irreversible weight loss rapidly increased with the increase of temperature. LiNi0.5Mn1.5O4 powders prepared at 900 ℃ for 12 h delivered the maximum discharge capacity of 134 mAh·g-1 with good cyclic performance at 2/7 C. In addition, by adjusting the calcination time at 900 ℃, the capacity and cycling performance of LiNi0.5Mn1.5O4 were further enhanced.展开更多
以Li2C O3,N iO和电解M nO2为原料,用固相法合成了LiN i0.5M n1.5O4。采用X R D,SEM和恒流充放电测试研究了合成样品的性能。X R D测试表明,在950℃下加热12h,然后600℃下退火48h,所得样品具有立方尖晶石结构。电化学测试表明,充放电曲...以Li2C O3,N iO和电解M nO2为原料,用固相法合成了LiN i0.5M n1.5O4。采用X R D,SEM和恒流充放电测试研究了合成样品的性能。X R D测试表明,在950℃下加热12h,然后600℃下退火48h,所得样品具有立方尖晶石结构。电化学测试表明,充放电曲线只在4.7V附近存在电压平台,但容量及循环性能有待于提高。展开更多
Effect of ball milling and electrolyte on the properties of high-voltage LiNi0.5Mn1.5O4 was investigated. Ball milling has significant effect on the synthesis and property of LiNi0.5Mn1.5O4. The X-ray diffraction（XRD...Effect of ball milling and electrolyte on the properties of high-voltage LiNi0.5Mn1.5O4 was investigated. Ball milling has significant effect on the synthesis and property of LiNi0.5Mn1.5O4. The X-ray diffraction（XRD） patterns indicate that LiNi0.5Mn1.5O4 cant be synthesized without ball milling even calcined at 900℃. When synthesized with ball milling, LiNi0.5Mn1.5O4 almost exhibits only one plateau at around 4.7V. With the increase of ball milling time, the capacity of (LiNi0.5Mn1.5O4) increases, but the cycling performance is not highly affected. The （electrochemical） property of (LiNi0.5Mn1.5O4) highly depends on the electrolyte. The stable and high-voltage-resistant （electrolyte） is much beneficial to enhancement of electrochemical property of LiNi0.5Mn1.5O4, such as coulombic efficiency and cycling performance.展开更多
Zn1-xMgxO （x = 0, 0.18） thin films were fabricated on the copper substrates by radiofrequency magnetron sputtering using the high pure argon as a sputtering gas. The Zn1-xMgxO films were characterized by X-ray powde...Zn1-xMgxO （x = 0, 0.18） thin films were fabricated on the copper substrates by radiofrequency magnetron sputtering using the high pure argon as a sputtering gas. The Zn1-xMgxO films were characterized by X-ray powder diffraction （XRD）, scanning electron microscope （SEM） and galvanostatic tests. The electrochemical test showed an improved electrochemical performance of Zn0.82EMg0.18O thin film as an anode material for lithium ion batteries.展开更多
A series of Li4Ti5O12 materials were prepared by three different methods： solvothermal, sol-gel, and solid-state reaction methods. Phase composition, morphology, and particle sizes of the samples were studied by powd...A series of Li4Ti5O12 materials were prepared by three different methods： solvothermal, sol-gel, and solid-state reaction methods. Phase composition, morphology, and particle sizes of the samples were studied by powder X-ray diffraction （XRD） and scanning electron microscopy （SEM）. Electrochemical properties of the samples were investigated by charge-discharge tests. It is demonstrated that both sol-gel and solid-state reaction methods provided good control over the chemical composition and microstructure of the active material, in which sol-gel method yielded a fine Li4Ti5O12 spinel having an initial specific capacity of 146 mAh g-1 and low capacity fade during cycling. Comparatively, the solid-state method is simple and promising to prepare Li4Ti5O12 for commercial applications.展开更多
以Li_2CO_3为锂源,采用纳米砂磨辅助固相合成了纯相LiNi_(0.8)Co_(0.15)Al_(0.05)O_2正极材料,研究了Li_2CO_3加入方式对所得样品结构、形貌以及电化学性能的影响.结果表明,加锂方式基本不影响材料的形貌和尺寸,但对材料的微结构和性能...以Li_2CO_3为锂源,采用纳米砂磨辅助固相合成了纯相LiNi_(0.8)Co_(0.15)Al_(0.05)O_2正极材料,研究了Li_2CO_3加入方式对所得样品结构、形貌以及电化学性能的影响.结果表明,加锂方式基本不影响材料的形貌和尺寸,但对材料的微结构和性能有明显的影响.纳米砂磨一步混合所有原料烧结所得LiNi_(0.8)Co_(0.15)Al_(0.05)O_2样品的阳离子混排程度比后研磨加碳酸锂烧结所得LiNi_(0.8)Co_(0.15)Al_(0.05)O_2样品的要低,更利于锂离子的扩散,对应的样品具有更高的放电比容量和库伦效率,但循环性能没有太大的差别.纳米砂磨一步混合所有原料在800℃烧结得到的LiNi_(0.8)Co_(0.15)Al_(0.05)O_2样品,1C循环首次放电比容量可达170.9 m Ah/g,50次循环后容量保持率为92.6%.展开更多
文摘Well-developed crystalline LiNi0.5Mn1.5O4 was prepared by solid-state reaction using Li2CO3, NiO and electrolytic MnO2 at high heating and cooling rate. X-ray diffraction (XRD) patterns and scanning electron microscopic (SEM) images showed that LiNi0.5Mn1.5O4 synthesized at 900 ℃ and 950 ℃ had cubic spinel structure with clearly defined shape. LiNi0.5Mn1.5O4 spinel phase decomposed at 1 000 ℃ accompanying with structural and morphological degradation. TG measurement revealed that the weight loss during heating process could be mostly gained in cooling process, and the upward tendency of weight loss during heating process decreased, while that of irreversible weight loss rapidly increased with the increase of temperature. LiNi0.5Mn1.5O4 powders prepared at 900 ℃ for 12 h delivered the maximum discharge capacity of 134 mAh·g-1 with good cyclic performance at 2/7 C. In addition, by adjusting the calcination time at 900 ℃, the capacity and cycling performance of LiNi0.5Mn1.5O4 were further enhanced.
文摘以Li2C O3,N iO和电解M nO2为原料,用固相法合成了LiN i0.5M n1.5O4。采用X R D,SEM和恒流充放电测试研究了合成样品的性能。X R D测试表明,在950℃下加热12h,然后600℃下退火48h,所得样品具有立方尖晶石结构。电化学测试表明,充放电曲线只在4.7V附近存在电压平台,但容量及循环性能有待于提高。
文摘Effect of ball milling and electrolyte on the properties of high-voltage LiNi0.5Mn1.5O4 was investigated. Ball milling has significant effect on the synthesis and property of LiNi0.5Mn1.5O4. The X-ray diffraction（XRD） patterns indicate that LiNi0.5Mn1.5O4 cant be synthesized without ball milling even calcined at 900℃. When synthesized with ball milling, LiNi0.5Mn1.5O4 almost exhibits only one plateau at around 4.7V. With the increase of ball milling time, the capacity of (LiNi0.5Mn1.5O4) increases, but the cycling performance is not highly affected. The （electrochemical） property of (LiNi0.5Mn1.5O4) highly depends on the electrolyte. The stable and high-voltage-resistant （electrolyte） is much beneficial to enhancement of electrochemical property of LiNi0.5Mn1.5O4, such as coulombic efficiency and cycling performance.
基金Financially supported by the Knowledge Innovation Program of Chinese Academy of Sciences, NNSFC (20831004 and 20771101)CAS Directional Program (No. KJCXZ-YW-M05)a funding from FJIRSM (SZD08002-3)
文摘Zn1-xMgxO （x = 0, 0.18） thin films were fabricated on the copper substrates by radiofrequency magnetron sputtering using the high pure argon as a sputtering gas. The Zn1-xMgxO films were characterized by X-ray powder diffraction （XRD）, scanning electron microscope （SEM） and galvanostatic tests. The electrochemical test showed an improved electrochemical performance of Zn0.82EMg0.18O thin film as an anode material for lithium ion batteries.
基金financially supported by NNSFC (No. 20773132, 20771101, 20831004)National Basic Research Program of China (No.2009CB939801)+1 种基金the Knowledge Innovation Program of the Chinese Academy of SciencesFJIRSM Key Program (No. SZD-09003-1)
文摘A series of Li4Ti5O12 materials were prepared by three different methods： solvothermal, sol-gel, and solid-state reaction methods. Phase composition, morphology, and particle sizes of the samples were studied by powder X-ray diffraction （XRD） and scanning electron microscopy （SEM）. Electrochemical properties of the samples were investigated by charge-discharge tests. It is demonstrated that both sol-gel and solid-state reaction methods provided good control over the chemical composition and microstructure of the active material, in which sol-gel method yielded a fine Li4Ti5O12 spinel having an initial specific capacity of 146 mAh g-1 and low capacity fade during cycling. Comparatively, the solid-state method is simple and promising to prepare Li4Ti5O12 for commercial applications.
文摘以Li_2CO_3为锂源,采用纳米砂磨辅助固相合成了纯相LiNi_(0.8)Co_(0.15)Al_(0.05)O_2正极材料,研究了Li_2CO_3加入方式对所得样品结构、形貌以及电化学性能的影响.结果表明,加锂方式基本不影响材料的形貌和尺寸,但对材料的微结构和性能有明显的影响.纳米砂磨一步混合所有原料烧结所得LiNi_(0.8)Co_(0.15)Al_(0.05)O_2样品的阳离子混排程度比后研磨加碳酸锂烧结所得LiNi_(0.8)Co_(0.15)Al_(0.05)O_2样品的要低,更利于锂离子的扩散,对应的样品具有更高的放电比容量和库伦效率,但循环性能没有太大的差别.纳米砂磨一步混合所有原料在800℃烧结得到的LiNi_(0.8)Co_(0.15)Al_(0.05)O_2样品,1C循环首次放电比容量可达170.9 m Ah/g,50次循环后容量保持率为92.6%.
