采用倒相法制备了二次锂电池用的聚偏氟乙烯–六氟丙烯复合聚合物(PVDF-HFP/SiO2)隔膜,测定了它的吸液率、电导率、机械强度等性能,并通过扫描电镜对其形貌进行了分析。研究结果表明, PVDF-HFP/SiO2隔膜具有较高的吸液率、电导率和韧性:电解质吸收率达184.4%、
室温电导率为1.20mS/cm、断裂伸长率高达163%。利用PVDF-HFP/SiO2隔膜装配的二次锂电池的首放比容量为834.8mAh/g,第40次的放电比容量达到400mAh/g, 循环效率达到99.8%以上,表现出良好的电化学性能。
Abstract
A polymer (PVDF-HFP) separator and a composite polymer (PVDF-HFP/SiO2) separator were prepared by the phase-inversion method. The electrolyte uptake, conductivity and mechanical properties of the separators were studied, and the corresponding micro-structures were examined by SEM. The PVDF-HFP/SiO2 separator exhibits much higher electrolyte uptake, conductivity and ductibility with an electrolyte uptake volume of 184.4%, a conductivity of 1.2 mS/cm and ductibility of 163%. When the PVDF-HFP/SiO2 separator is employed in a lithium battery a good cycle performance and a high cycling fficiency are observed. The first discharge specific capacity is 834.8 mAh/g, the 40th cycle discharge capacity is 400 mAh/g and the average charge/discharge efficiency is above 99.8%.
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参考文献
[1] Wachtler M, Ostrovskii D, Jacobsson P, et al. A study on PVDF-based SiO2-containing composite geltype polymer electrolytes for lithium batteries [J]. Electrochimica Acta, 2004,50(11):356-360.
[2] Appetecchi G B, Romagnoli P, Serosati B. Composite gel separators: a
new class of improved polymer electrolytes for lithium batteries [J]. Electroc
hemistry Communications, 2001,3(6):281-284.
[3] Wang Zhang-liang, Tang Zhi-yuan. A novel polymer electrolyte based
on PMAML/PVDF-HFP blend [J]. Electrochimica Acta,2004,49(3): 1063-1068.
[4] Young Tai-horng, Chen Leo-wang. Pore formation mechanism of separat
ors from phase inversion process [J]. Desalination, 1995,103(11): 233-247.
[5] 任旭梅,吴锋,白莹,等.倒相法制备多孔PVDF隔膜的条探索[J].电化学,2001,7(4): 501-505.
[6] Kumar W, Scanlon L G. Polymerceramic composite electrolytes [J].
Power Sources,1995,52(11): 261-268.
[7] Etecchi G B, Croce F, Romagnoli P, et al. High-performance gel-type lithiu
m electrolyte separators [J]. Electrochemistry Communications, 1999, 1(2): 83
-86.
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脚注
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