排序方式: 共有17条查询结果,搜索用时 15 毫秒
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Pengjian Zuo Tao Wang Guangyu Cheng Chunyu Du Yulin Ma Xinqun Cheng Geping Yin 《Journal of Solid State Electrochemistry》2013,17(7):1955-1959
Li2FeSiO4/C cathode materials have been prepared using the conventional solid-state method by varying the sintering temperature (650 °C, 700 °C and 750 °C), and the structure and electrochemical performance of Li2FeSiO4/C materials are investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), galvanostatic charge–discharge tests, respectively. The results show that Li2FeSiO4 nano-crystals with a diameter of about 6–8 nm are inbedded in the amorphous carbon, and the Li2FeSiO4/C material obtained at 700 °C exhibits an initial discharge capacity of 195 mA?h g?1 at 1/16 C in the potential range of 1.5–4.8 V. The excellent electrochemical performance of Li2FeSiO4/C attributes to the improvement of conductivity and reduction of impurity by the optimization of the sintering temperature. 相似文献
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The in-depth analyses of polarisation interferometry flying height testing are presented. The drawbacks of the oblique incidence polarisation interferometry method are discussed. The application of the dual-beam normal incidence polarisation interferometry method is illustrated. It is shown that with this normal incidence polarisation interferometer, not only the flying height can be measured down to contact without losing accuracy, but the optical parameters of the head-slider can also be determined. 相似文献
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Lingling Zhang Yulin Ma Lei Du Geping Yin Xinqun Cheng Peng Fan Qiang Fu Jilong Liu Bin Qu 《Journal of Solid State Electrochemistry》2018,22(12):3743-3750
The accidental overcharging is emulated in fully charged LiCoO2/mesocarbon microbeads (MCMB) batteries through initial one-off overcharging and successive long-term normal cycling. The aging mechanism and effect of accidental overcharging on the performance of LiCoO2/MCMB battery is studied by the electrochemical tests and physical characterizations. The result clearly shows that not all accidentally overcharged batteries should be discarded and the extent of the degradation is highly dependent on the overcharging cutoff voltages. Compared with the blank batteries, low overcharging cutoff voltages have almost no influence on the performance degradation during successive long-term normal cycling. Under this condition, the aging is primarily due to the consumption of active lithium. However, high overcharging cutoff voltages, even just one time, decay the battery. Furthermore, further cycling accelerates the aging and changes the aging mechanism of battery under normal operation condition. Under this condition, the surface structure destruction of the LiCoO2 is revealed as the primary contributor to battery degradation, which is related to the dissolution and reduction of cobalt ions after overcharging at high cutoff voltages and successive long-term normal cycling. 相似文献
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Geng Tianfeng Du Chunyu Cheng Xinqun Xu Xing Jian Jiyuan He Xiaoshu Zuo Pengjian Yin Geping 《Journal of Solid State Electrochemistry》2019,23(1):101-108
Journal of Solid State Electrochemistry - Li-rich layered oxide (LrLO) cathode has attracted much attention for Li-ion batteries in recent years due to its superior capacity of exceeding... 相似文献
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Zuguang Ying Xinqun Zhu 《Acta Mechanica Solida Sinica》2009,22(2):152-160
The random response of a piezoelectric thick shell in plane strain state under boundary random excitations is studied and illustrated with a piezoelectric cylindrical shell. The differential equation for electric potential is integrated radially to obtain the electric potential as a function of displacement. The random stress boundary conditions are converted into homogeneous ones by transformation,which yields the electrical and mechanical coupling differential equation for displacement under random excitations. Then this partial differential equation is converted into ordinary differential equations using the Galerkin method and the Legendre polynomials,which represent a random multi-degree-of-freedom system with asymmetric stiffness matrix due to the electrical and mechanical coupling and the transformed boundary conditions. The frequency-response function matrix and response power spectral density matrix of the system are derived based on the theory of random vibration. The mean-square displacement and electric potential of the piezoelectric shell are finally obtained,and the frequency-response characteristics and the electrical and mechanical coupling properties are explored. 相似文献
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In this paper, a dual-beam normal incidence polarisation interferometer is proposed to measure the flying height or head–disk spacing. Using this interferometer, the head–disk spacing can be measured both in magnetic real disk condition and in glass disk condition. It has the advantage of both the currently popular intensity interferometry method and the oblique incidence polarisation interferometry method. With this polarisation interferometer, not only the flying height can be measured down to contact without losing accuracy, but the pitch and roll of the head-slider can also be detected dynamically. The optical parameters of the head-slider can also be determined. Design details and experimental study are presented. 相似文献
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给出了计算粉尘层流火焰速度的直接方法,此法简便易行,在粉尘浓度较低时,计算精度较高。实验结果表明:粉尘浓度对火焰传播速度和燃烧速度有很大的影响,粉尘浓度过大时,粒子运动轨迹就难观测,用直接法计算层流火焰速度的误差增大;管径大小也对燃烧速度有很大影响;小管径中的所得值比大管径中的所得值约低8%。 相似文献
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Xinqun Zhang Jian Gao Yukun Xiao Jiaqi Wang Guoqiang Sun Yang Zhao Liangti Qu 《化学:亚洲杂志》2020,15(15):2271-2281
Benefiting from unique excellent physical and chemical characteristics, graphene has attracted widespread attention in the application of electrocatalysis. As a promising candidate, graphene is usually regulated with surface defects, heteroatoms, metal atoms and other active materials through covalent or non‐covalent bonds to substitute for noble metal catalysts, which has not been targeted in a report yet. In this review, we summarize the recent advances of approaches for engineering graphene‐based electrocatalysts and emphasize the corresponding electrocatalytic active sites in various electrocatalysis circumstances, such as electrocatalytic hydrogen evolution reaction (HER), oxygen evolution reaction (OER), oxygen reduction reaction (ORR), etc. The opportunities and challenges in the future development of graphene‐based catalysts are also discussed. 相似文献