NiO纳米晶的制备和电化学性能

Preparation and electrochemical properties of nanocrystalline NiO

用溶胶-凝胶(Sol-Gel)工艺制备纳米NiO粉体,研究了烧结温度对其结构和电化学性能的影响.结果表明,以醋酸镍、柠檬酸、乙二醇为原料通过酯化-络合过程合成的凝胶,在烧结过程中在430℃完全分解并逐渐形成NiO纳米晶;随着烧结温度的升高,纳米NiO粉体的结构趋于完善、晶粒尺寸逐渐增大,其电化学循环性能逐渐提高;在600℃烧结2 h可得到平均粒径约为40 nm、呈球形的NiO纳米晶颗粒.NiO纳米晶的首次和第10次充放电比容量分别高达850 mAh/g和471 mAh/g,具有良好的容量保持率,明显优越于用固相法制备的NiO粉体.

The influence of sintering temperature on the morphology and structure of NiO powder prepared by sol-gel was explored and its electrochemical performance was preliminarily investigated. The results show that using nickel diacetate, citric acid and glycol as raw material, the stable sol and gel are synthesized by esterifying and chelatering reaction. The gel entirely decomposes at 430 ℃ and gradually forms the nanocrystalline NiO powder during heating treatment. With the increasing of sintering temper- ature, nanosized NiO powder exhibits larger and more uniform particle, more integrity crystal structure and high electrochemical cycling performance. The NiO powder consisted with 40 nm spherical particle is fabricated by sinterring gel at 600℃for 2 h possessing high initial and 10th discharge special capacity of 850 mAh/g and 471 mAh/g, which is obviously superior to that obtained by solid phase method in electrochemistry properties.