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锂离子电池正极材料Li1+xV3O8的研究进展 总被引:1,自引:0,他引:1
层状结构材料Li1 xV3O8有可能成为新一代锂离子电池正极材料。综述了锂离子电池正极材料的结构特点,重点介绍了国内外Li1 xV3O8的几种合成方法,分析了Li1 xV3O8的掺杂改性研究,总结了正极材料Li1 xV3O8的充放电工作原理,并展望了锂离子电池正极材料Li1 xV3O8未来应用前景。 相似文献
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用甘氨酸络合制备锂离子电池正极材料Li1+xV3O8,并通过镧掺杂对材料进行改性。电化学测试表明,合成的Li1+xV3O8在室温下以10mA/g的电流放电时,其比容量高达360mAh/g;当掺杂La后,正极材料Li1+xV3-yLayO8的电导率和循环性能均比未掺杂时提高,但初始容量有所降低。采用X射线衍射光谱法(XRD)测试了正极材料Li1+xV3-yLayO8(y=0、0.02、0.04、0.06)的结构,发现La掺杂能使该正极材料的各晶面衍射峰强度增加;用扫描电子显微镜法(SEM)对充放电前后的正极材料Li1+xV3-yLayO8的形貌进行测试,发现15次循环后该材料的表面形貌发生很大的变化。 相似文献
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以氢氧化锂、醋酸亚铁和硼酸为原料,利用柠檬酸作螯合剂和碳源,采用流变相法,合成了新型正极材料LiFeBO_3和LiFeBO_3/C。利用XRD、SEM等对材料的结构和形貌进行表征,结果表明:LiFeBO_3/C在形貌上比LiFeBO_3的颗粒分布更加均匀;电化学性能测试研究结果表明:LiFeBO_3/C样品的循环稳定性较好,具有高的充放电比容量,初始放电比容量为120.3 m Ah/g,具有较高的可逆比容量和优良的循环性能。该正极材料合成原料价格低廉,循环性能好,作为锂离子电池正极材料具有很高的可行性。 相似文献
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锂离子电池正极材料Li-Ni-Go-Mn-O化合物研究 总被引:2,自引:0,他引:2
3G时代的数码产品和电动汽车要求锂离子电池具有高比容量、高循环性能、低成本和环保的特点,Li-Ni-Co-Mn-O化合物就是在这种趋势下开发出来潜在替代LiCoO2的锂离子电池正极材料,且近年来成为研究热点。综述了Li-Ni-Co-Mn-O化合物作为锂离子电池正极材料的研究,同时以LiNi1/3Co1/3Mn1/3O2为例介绍该系列化合物的结构研究情况。重点阐述了Li-Ni-Co-Mn-O化合物的合成方法、Li:M(eMe=Ni Co Mn)对其性能的影响、Me在该化合物中的作用,最后介绍了Li-Ni-Co-Mn-O化合物的表面处理与掺杂研究进展情况和应用前景。 相似文献
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富锂锰基正极材料xLiMO_2·(1-x)Li_2MnO_3凭借其比容量高、工作电压高、对环境更友好,有望成为下一代高比能量电池的优选正极材料。总结了富锂锰基正极材料存在的问题,介绍了富锂锰基正极材料的改性研究进展及制备方法,展望了富锂锰基正极材料的应用和发展方向。 相似文献
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The possibility of realizing a low-voltage and low-power audio-band Σ Δ modulator has been studied. The current-mode circuit technique has been adopted to enable the modulator to operate at less than 3 V supply voltage. The modulator to uses analog integrators instead of switched-capacitor-type integrators to avoid the use of analog switches, which allows low-voltage operation of the modulator circuit. A newly designed voltage-to-current converter is used to form an analog integrator. The designed circuit was actually fabricated by using a CMOS 0.6 μm process and its characteristics were evaluated. A signal-to-noise ratio of 68 dB in a 20 kHz bandwidth for the first-order modulator construction was measured from the 2.5 V supply voltage at an oversampling ratio of 256. However, only 72 dB of the signal-to-noise ratio and 65 dB of distortion were measured for the second-order modulator construction, although operation of the oversampling ratio of 48 was successfully confirmed. We concluded that low-voltage and low-power operation with less than 3 V of supply voltage is possible for the audio-band Σ Δ modulator, although signal-to-noise ratio and distortion issues in the 2nd-order configuration are left for future study. © 1998 Scripta Technica, Electr Eng Jpn, 124(1): 24–32, 1998 相似文献
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本文把边界电场约束方程法发展用于三维电场的数值分析。采用20个节点六面体的等参元,对大型三相电力变压器相间三维稳态电场进行了有限元分析,获得了任意时刻的边界场强和空间电场分布。并详细描述了具有对称结构的非对称场分布的稳态电场的分析方法 相似文献
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AbstractBa0.95Ca0.05Ti1-xZrxO3 (BCTZO) ceramics were prepared by a solid state reaction method. The samples were characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM) and X-ray absorption near edge structure (XANES). The ceramics exhibit a pure perovskite structure. The average grain size gradually decreases with increasing Zr concentration. XANES results indicate that the intensities of pre-edge peaks dropped with increasing Zr concentration. The BCTZO ceramic of x?=?0.05 has the optimum electrical properties with the maximum dielectric constant (ε'm), remanent polarization (2Pr), coercive electric field (2Ec) and piezoelectric charge constant (d33) of 7,244, 12.54 (μC/cm2), 5.29 (kV/cm) and 288 (pC/N), respectively. 相似文献
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Hiroyuki Nishikawa Eiki Watanabe Daisuke Ito Yoshimichi Ohki 《Electrical Engineering in Japan》1997,121(3):9-19
The formation mechanisms of paramagnetic defect centers in amorphous SiO2 induced by excimer lasers, 60Co γ rays, and mechanical fracturing were investigated. Correlation between the paramagnetic defect centers and their precursors introduced during manufacture is discussed for the cases of excimer lasers and γ rays. For the case of mechanical fracturing, formation of strained Si·O·Si bonds as well as paramagnetic defects is examined. The mechanism of laser- or γ-ray-induced paramagnetic defect centers is compared with that of fracture-induced centers. © 1998 Scripta Technica, Inc. Electr Erg Jpn, 121(3): 9–19, 1997 相似文献
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Mo Huang Dihu Chen Zhao Wang Jianping Guo Elias H. Dagher Bin Xu Ken Xu Hui Ye Weiguo Zheng Zhen Liang Xiaofeng Liang Wesley K. Masenten 《International Journal of Circuit Theory and Applications》2015,43(6):806-821
In this work, a power‐area‐efficient, 3‐band, 2‐RX MIMO, and TD‐LTE (backward compatible with the HSPA+, HSUPA, HSDPA, and TD‐SCDMA) CMOS receiver is presented and implemented in 0.13‐μm CMOS technology. The continuous‐time delta‐sigma A/D converters (CT ?Σ ADCs) are directly coupled to the outputs of the transimpedance amplifiers, eliminating the need of analog anti‐aliasing filters between RX front‐end and ADCs in conventional structures. The strong adjacent channel interference without low‐pass filter attenuation is handled by proper gain control. A low‐power small‐area solution for excess loop delay compensation is implemented in the CT ?Σ ADC. At 20 MHz bandwidth, the CT ?Σ ADC achieves 66 dB dynamic range and 3.5 dB RX chip noise figure is measured. A maximum of 2.4 dB signal‐to‐noise ratio degradation is measured in all the adjacent channel selectivity (ACS) and blocking tests, demonstrating the effectiveness of the strategy against the low‐pass filter removal from the conventional architecture. The receiver dissipates a maximum of 171 mW at 2‐RX MIMO mode. To our best knowledge, it is the first research paper on the design of fully integrated commercial TD‐LTE receiver. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献