科研之友
微信
新浪微博
Facebook
分享链接
摘要
Nowadays, the clean energy is of special concern researches owing to the unavoidable environmental pollutions. To satisfy the demand of sustainable development strategy, it is necessary to develop high-efficient and portable energy storage and conversion devices. Lithium ion batteries (LIBs) are considered as most promising electrochemical energy storage system in this era and are anticipated to power the mentioned applications. Herein, a facile and effective route has been developed for synthesis of CoO/reduced graphite oxide (RGO) composites as LIB anodes. In the synthesis, the GO prepared by the modified Hummers' method was dissolved into deionized water, and then mixed with Co(NO3)(2) solution. Subsequently, the obtained homogeneous solution was transferred into 100 mL Teflon-lined stainless-steel autoclave. The sealed autoclave was putted into an oven at 160 degrees C for 6 h. After cooled down to room temperature, the precursor of depositions were filtered, washed with deionized water and dried at 80 degrees C. Finally, the precursor was thermal treated at 500 degrees C for 2 h in a tube furnace under nitrogen ambient to obtain the final product of CoO/RGO composites. The synthetic composites were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). XRD patterns proved that the composites were composed of CoO and graphene. SEM images indicated the CoO nanoparticles grown on the graphene nanosheets uniformly. The CoO nanoparticles loaded on the surface of graphene nanosheets could prevent the aggregation of graphene. Meanwhile, the graphene nanosheets could combine with each other to form a large 3D electron conductive network, which can promote the electrical conductivity of the composite. The LIB was assembled in glove-box, in which the composite electrode and metal lithium plate were used as the anode and the cathode, respectively. The electrochemical test results imply that the initial discharge specific capacity could be up to 1312.6 mAh.g(-1) at a current density of 100 mA.g(-1). Notably, the discharge specific capacity is still about 557.4 mAh.g(-1) after 300 cycles at a high current density of 10000 mA.g(-1). It is demonstrated that the composite exhibits high specific capacity, excellent rate capability and well cyclic stability. The 3D network could be used as a stable framework to accommodate the volume change of active material during Li+ insertion/extraction, which play important role for the superior electrochemical performance.
- 出版日期2017-2-15
- 单位黑龙江大学
