(大連理工大學(xué) 材料科學(xué)與工程學(xué)院，三束材料改性教育部重點實驗室，大連 116024)
摘 要: 以微米Al粉和Fe粉為原料，采用直流電弧等離子體氣相蒸發(fā)法，在氫氬和不同CH4含量氣氛下制備了Al-Fe和Al-Fe-C納米復(fù)合粒子。研究納米粉體的形成機制、結(jié)構(gòu)、形貌及其電化學(xué)性能，著重研究C原子的加入對納米粒子產(chǎn)物的成分組成、相結(jié)構(gòu)及電化學(xué)性能的影響，對各種納米粒子形成規(guī)律及嵌/脫鋰電化學(xué)機制進行了探討。結(jié)果表明：無碳?xì)夥障轮苽涞腁l-Fe粒子呈球狀；在含碳?xì)夥障拢S著C含量的提高，粒子形貌向柱狀和線狀發(fā)展，粉體相組成由Al向Al4C3轉(zhuǎn)變，合金種類由FeAl2向Fe2Al5轉(zhuǎn)變。當(dāng)電流密度為100 mA/g時，4種復(fù)合材料電極的首次放電容量分別為348.8、193.3、275.5和628.8 mA？h/g，金屬間化合物Fe2Al5相的形成有利于提高充/放電容量和抑制體積變化，有效提高了電極的循環(huán)穩(wěn)定性能。
關(guān)鍵字: Al-Fe/C；納米復(fù)合材料；鋰離子電池；負(fù)極材料；直流電弧法
（School of Materials Science and Engineering, Key Laboratory of Materials Modification by Laser, Ion, and Electron Beams, Dalian University of Technology, Dalian 116024, China）
Abstract:Al-Fe and Al-Fe-C nanocomposite particles were prepared through DC arc-discharge method under a methane atmosphere with micro-sized aluminium and iron powders as the raw materials. The formation mechanism, structures, morphologies and electrochemical performances of the nanoparticles’ samples were studied. The effects of carbon atoms on the composition, phase structure and electrochemical properties were studied, and the formation mechanism of nanoparticles as well as electrochemical intercalation/deintercalation of lithium ions were also discussed. The results indicate that the Al-Fe particles prepared in a carbon-free atmosphere are spherical in shapes, meanwhile, the carbon-containing atmosphere causes the morphology of particles columnar or linear, the composition changes from Al to Al4C3 and from FeAl2 to Fe2Al5 in Al-Fe-C nanocomposite particles. The first discharge capacities of four kinds of nanoparticles’ electrodes are 348.8, 193.3, 275.5 and 628.8 mA？h/g, under the current density of 100 mA/g, respectively. The presence of intermetallic Fe2Al5 in the powders favors to improve the capacities and restrain the volume changes during the intercalation/deintercalation of lithium ions, thus the cycle stability of electrode was greatly enhanced.
Key words: Al-Fe/C; nanocomposite; lithium ion battery; anode; DC arc-discharge method
