(中南大學(xué) 冶金與環(huán)境學(xué)院，長(zhǎng)沙 410083)
摘 要: 以聚乙烯基吡咯烷酮(PVP)與聚偏氟乙烯-六氟丙烯[P(VDF-HFP)]的共混物為基質(zhì)，通過溶劑揮發(fā)法制備聚合物微孔膜，將其浸取電解液后制成聚合物電解質(zhì)并組裝LiCoO2/Li聚合物鋰離子電池。采用掃描電子顯微鏡、差熱-熱重分析、交流阻抗、線性伏安掃描等技術(shù)對(duì)制備的聚合物微孔膜及電解質(zhì)進(jìn)行表征，采用恒流充放電方法對(duì)組裝的聚合物鋰離子電池進(jìn)行電化學(xué)性能測(cè)試。結(jié)果表明：溶劑揮發(fā)法制得的聚合物膜孔穴豐富，液態(tài)電解質(zhì)吸液率可達(dá)到480%；浸取電解液后獲得的聚合物電解質(zhì)室溫離子電導(dǎo)率為4.79×10-3 S/cm，電化學(xué)穩(wěn)定窗口為5.5 V；基于該聚合物電解質(zhì)裝配的LiCoO2/Li電池在0.1C倍率充放電時(shí)，首次放電容量為142.37 mA？h/g，放電平臺(tái)約為3.86 V，30次循環(huán)后容量仍保持有136.68 mA？h/g，庫侖效率穩(wěn)定在97%左右。
關(guān)鍵字: 聚合物電解質(zhì)；微孔膜；鋰離子電池；溶劑揮發(fā)法；P(VDF-HFP)；PVP
（School of Metallurgy and Environment, Central South University, Changsha 410083, China）
Abstract:A kind of microporous membrane based on the blend of PVP and P (VDF-HFP) was prepared by solvent evaporation method, and the LiCoO2/Li polymer batteries were assembled with the microporous membrane which absorbed electrolyte. The polymer membrane and electrolyte were characterized by scanning electronic morphology (SEM), differential scanning calorimeter-thermo gravimetry (DSC-TG), electrochemical impedance spectroscopy (EIS) and linear scanning voltammetry (LSV). The electrochemical performance of LiCoO2/Li polymer battery was tested by charge-discharge test with constant current. The results show that this polymer membrane has abundant micro pores and exhibits up to 480% uptake of liquid electrolyte. The ionic conductivity of the polymer electrolyte is 4.79×10-3 S/cm at room temperature and its electrochemical stable window is 5.5 V. The LiCoO2/Li battery based on the polymer electrolyte displays an initial discharge capacity of 142.37 mA？h/g and discharge plateau of about 3.86 V at 0.1C. After 30 cycles, its discharge capacity remains 136.68 mA？h/g, and coulombic efficiency stays around 97%.
Key words: polymer electrolyte; microporous membrane; Li-ion battery; solvent evaporation method; P(VDF-HFP); PVP
