Discharge Rate Capability of the LiCoO2 Electrode
Discharge Rate Capability of the LiCoO2 Electrode
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DOI：
10.1149/1.1838289
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发表时间：
1998-02
影响因子：
3.9
通讯作者：
K. Abraham;D. M. Pasquariello;E. Willstaedt
中科院分区：
文献类型：
--
作者：
K. Abraham;D. M. Pasquariello;E. Willstaedt
LiCoO{sub2}是一种很高倍率的阴极。Li/LiCoO{sub2}电池的功率密度高达5500W/kg。用直径为5{Micro}m或更小直径的LiCoO{sub2}粒子制作的约75-{Micro}m厚的电极可获得如此高的功率，并且具有约65%的孔隙率。电解液为2M LiAsF{sub6}溶液，混合溶剂为25%碳酸亚丙酯和75%乙酸甲酯。该电解液具有较高的Li{sup+}浓度，其室温电导率为2{次}10{sup{负}2}{欧米茄}{sup{负}1}cm{sup{负}1}，使得Li/LiCoO{sub2}电池的放电电流高达100 mA/cm{sup2}。在50 mA/cm{sup 2}和较高的电流密度下，LiCoO{sub2}的利用率与隔膜孔隙率有很强的相关性。具有约55%孔隙率的25微米厚的隔板的电池比具有32%孔隙率的相同厚度的隔板的电池具有显著更好的功率输出。
LiCoO{sub 2} is shown to be a very high rate cathode. Power densities as high as 5,500 W/kg have been demonstrated for Li/LiCoO{sub 2} cells. Such high power was obtained with approximately 75-{micro}m-thick electrodes fabricated with 5 {micro}m or smaller diameter LiCoO{sub 2} particles and having about 65% porosity. A 2 M solution LiAsF{sub 6} in a mixed solvent consisting of 25 vol% propylene carbonate and 75 vol% methyl acetate was the electrolyte. The high Li{sup +} concentration of this electrolyte, together with its room temperature conductivity of 2 {times} 10{sup {minus}2} {Omega}{sup {minus}1} cm{sup {minus}1}, allowed the discharge of Li/LiCoO{sub 2} cells at currents as high as 100 mA/cm{sup 2}. The LiCoO{sub 2} utilization at 50 mA/cm{sup 2} and higher current densities showed a strong dependence on separator porosity. Cells with a 25-{micro}m-thick separator having about 55% porosity showed significantly better power output than ones containing a separator of the same thickness having 32% porosity.