(中南大學(xué) 冶金科學(xué)與工程學(xué)院，長沙 410083)
摘 要: 研究化學(xué)鍍Ni、Cu和混合摻雜Zn處理后天然鱗片石墨的電化學(xué)嵌/脫鋰性能。結(jié)果表明：金屬微粒Ni、Cu與Zn的摻入可有效改善天然鱗片石墨的循環(huán)性能與大倍率充放電特性，金屬微粒有效降低石墨電極內(nèi)阻、保證石墨顆粒之間緊密的電接觸是摻入金屬微粒后石墨大倍率充放電性能得到改善的重要原因之一。Ni與Cu微粒改善石墨循環(huán)性能的機理與Zn的不同，Cu、Ni通過阻止溶劑化鋰離子嵌入維持石墨結(jié)構(gòu)穩(wěn)定性，來達(dá)到提高材料循環(huán)性能的目的；金屬Zn改善石墨循環(huán)性能的原因則可能是嵌鋰過程中，Zn鋰化所形成Li-Zn合金維持材料表面所形成SEI膜的穩(wěn)定性。
關(guān)鍵字: 天然鱗片石墨；金屬微粒摻雜；鋰離子二次電池；嵌/脫鋰性能
（School of Metallurgical Science and Engineering, Central South University, Changsha 410083, China）
Abstract:The intercalation/deintercalation Li performances of natural flake graphite (NFG) doped with metal particles, such as Ni, Cu and Zn, were studied. The experimental results show that the metal particles are effective to improve cycling behavior and rate performance of NFG. One of the main reasons for these phenomena is that the metal particles can effectively reduce the graphite electrode resistance and accordingly ensure intimate contact between graphite particles. The mechanism of that Ni and Cu can improve the cycling behavior of NFG is different from that of Zn. The electroless Ni and Cu on the surface of graphite can effectively prevent the intercalation of solvated Li ion and maintain the structure stability of graphite, thus improve the cycling behavior. The reason that Zn doping improves cycling behavior of graphite is probably for the formation of Zn-Li alloy from the Zn lithiation reaction during the intercalation process which is beneficial to form stable SEI film on the surface of carbon electrode.
Key words: natural flake graphite; metal particles doping; lithium ion secondary battery; intercalation/deintercalation Li performance
