(中南大學(xué) 材料科學(xué)與工程學(xué)院，長沙 410083)
摘 要: 鋰離子電池因為其較高的能量密度、優(yōu)良的循環(huán)性能及較強的荷電保持能力被廣泛應(yīng)用于便捷式電子器件中。同時作為混合動力汽車(HV)和電動汽車(EV)潛在的電源設(shè)備也被廣泛地研究，但是，目前其電化學(xué)性能還不能完全滿足高能量密度、大功率的要求。主要是因為商品化和即將進入開發(fā)性研究的正極材料大多是嵌鋰過 渡金屬氧化物，這些正極材料存在致命的本征制約 —— 較低的比容量。釩基正極材料，如V2O5、LiV3O8和Li3V2(PO4)3等，由于可以嵌入多個Li+離子，從而具有較高的理論比容量，但受材料微結(jié)構(gòu)的影響，這類材料的實際比容量遠低于理論值。材料微結(jié)構(gòu)納米化，可以形成獨特形貌，獲得高比表面積，縮短Li+離子的擴散距離，使這類材料的實際比容量接近理論值，從而有可能在能量的高效率儲存中扮演十分重要的角色。本文作者重點綜述釩基正極材料的主要晶體結(jié)構(gòu)特點和相關(guān)納米材料合成方法、結(jié)構(gòu)表征及其對應(yīng)電化學(xué)性能的研究進展。
關(guān)鍵字: 納米材料；鋰離子電池；V2O5；LiV3O8；Li3V2(PO4)3；電化學(xué)性能
cathodes for lithium batteries
（School of Materials Science and Engineering, Central South University, Changsha 410083, China）
Abstract:Lithium-ion batteries (LIBs) were widely used in portable electronic devices, mainly due to their high energy density, good cycle performance and charge retention ability. Moreover, as the potential power sources of the hybrid vehicles (HV) and electric vehicles (EV), LIBs were widely studied. But at present their electrochemical properties cannot fully meet the requirements of high energy density, high power for power sources of HV and EV. This is mainly because most commercial and studied cathode materials are lithium transition metal oxides, which have an intrinsic constraint, i.e. low capacity. V-based cathode materials, such as V2O5, LiV3O8 and Li3V2(PO4)3, possess relatively high theoretical specific capacity because of their abilities to intercalate more Li+ ions per formula. However, due to the structure limitation of these materials, their actual capacity is much lower than the theoretical value. Synthesis of these materials with nanostructures can greatly enlarge their surface areas and reduce the Li+ ion diffusion distance significantly, resulting in the fact that the actual specific capacity is closer to the theoretical value. Such V-based nanomaterials may make LIBs play an important role in the high efficiency store of energy, especially for power sources of HV and EV. This review focuses on the research development of synthesis of V-based nanomaterials, characterization and their corresponding electrochemical properties.
Key words: nanomaterials; lithium ion batteries; V2O5; LiV3O8; Li3V2(PO4)3; electrochemical performance
