(湖南大學(xué) 材料科學(xué)與工程學(xué)院，長沙 410082)
摘 要: 通過原位聚合法，制備一系列的導(dǎo)電聚合物(Polyaniline，PANI)的LiFePO4/PANI復(fù)合材料。單用傅里葉紅外光譜(FTIR)和高分辨透射電鏡(HRTEM)表征PANI與LiFePO4之間的相互作用以及PANI對LiFePO4的包覆狀況。采用四探針、電化學(xué)阻抗譜及恒電流充放電測試復(fù)合材料的電導(dǎo)率及其電化學(xué)性能。結(jié)果表明：當(dāng)PANI含量為6.75%(質(zhì)量分數(shù))時，能在LiFePO4的表面形成均勻的包覆層，試樣具有最佳的電化學(xué)性能，電荷轉(zhuǎn)移電阻較小，交換電流較大，C/12倍率下首次放電容量為151.97 mA∙h/g，并具有較好的循環(huán)性能及倍率性能。
關(guān)鍵字: 鋰離子電池；正極材料；復(fù)合材料；磷酸鐵鋰；聚苯胺
（College of Materials Science and Engineering, Hunan University, Changsha 410082, China）
Abstract:A series of conductive polymer LiFePO4/polyaniline composites were synthesized through in-situ polymerization. The interaction between PANI and LiFePO4 and the coating situation between PANI and LiFePO4 were characterized by Fourier infrared spectroscopy (FTIR) and high resolution transmission electron microscopy (HRTEM). The four-probe methods, electrochemical impedance spectroscopy and galvanotactic current charge and discharge methods were used to test the electronic conductivity and electrochemical performance of the composites, respectively. The results show that evenly coated layers are formed when the content of PANI reaches 6.75% (mass fraction) with the best electrochemical performance, lower charge transfer resistance and larger exchange current. The initials discharge capacity is 151.97 mA∙h/g at the discharge rate of C/12 with good rate and cycling capability.
Key words: lithium ion batteries; cathodes; composite; LiFeO4; polyaniline
