摘要
应用溶液还原法合成超细非晶态合金Fe B和Co B粒子,并研究这类材料的电化学行为.结果表明,尽管碱性溶液中单质硼和钴表现为电化学惰性,而单质铁的电化学活性很低,但Fe B和Co B却表现出特殊的电化学活性和放电容量.在100mA/g的恒流放电条件下,Co B和Fe B的比容量分别为1100mAh/g和1200mAh/g,远高于单质金属或硼元素预期的放电容量.这种超细非晶态合金(UAAP)电极的电化学活性可能来自于金属硼化物的电子性质,非晶态特征与纳米尺度的协同效应,前两因素使硼元素的活化和电子导电性得到改善,后者则增强了材料的反应活性和电化学利用率.
Ultrafine amorphous alloy particles (UAAP) of Fe-B and Co-B were synthesized and tested for possible use as electroactive anode materials. It is found that unlike their parent elements, the alloy particles of transition metal (TM) and boron, the Fe-B and Co-B showed superior electrochemical activities when used as anodic materials in aqueous alkaline solution. The discharge capacities of Fe-B and Co-B electrodeswere observed to be 1 200 mAh/gand 1 100 mAh/gat moderately high rate of 100 mAh/g, respectively, much higher than the theoreticalcapacity of currently used zinc metal (820 mAh/g). The exceptional high capacities of the boride alloys were probably due to the electrochemicalactivation of boron atoms in the highly dispersed transition metal atoms, the better conductivity and the existence of finite ionic bond in UAAP.
出处
《电化学》
CAS
CSCD
2004年第2期175-180,共6页
Journal of Electrochemistry
基金
国家 97 3计划 (2 0 0 2CB2 1 1 80 5)资助
