中文摘要：

针对目前的锂离子电池负极材料存在比容量低、循环稳定性差等问题，本工作发展了简单、有效的方法合成氧化亚钴纳米粒子与石墨烯的复合材料（CoO／RGO）．采用氧化石墨（GO）和Co（NO3）2作为原料，先用水热路线制备了前驱体，再将其在氮气气氛下热处理，最终得到CoO／RGO复合材料．存在于石墨烯表面的CoO纳米粒子可以有效地阻止石墨烯片层的聚集，同时石墨烯片层的相互连接能够形成三维的空间网络，提高复合材料的导电性．将合成的CoO／RGO复合材料作为负极，以锂片作为正极，组装成纽扣电池．电化学测试表明，在电流密度为100mA·g-1的条件下，初始比容量放电比容量高达1312．6mAh·g-1，在10000mA·g-1的大电流密度下，经过300圈循环后，其比容量仍然可以达到557．4mAh·g-1．这表明CoO／RGO复合材料具有高的比容量、优异的倍率性能及循环稳定性，这归因于3D网状结构能够避免在锂离子的嵌入／脱出过程中材料的结构被严重破坏．

英文摘要：

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 ℃ for 6 h. After cooled down to room temperature, the precursor of depositions were filtered, washed with deionized water and dried at 80 ℃. Finally, the precursor was thermal treated at 500 ℃ 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 ofgraphene. 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·