中文摘要：

首次报道了一种新颖的基于乙醇溶液的一步草酸共沉淀法合成富锂锰基正极材料的方法。在这种方法中,包括锂元素在内的所有元素均能在共沉淀反应步骤发生沉淀反应,以此实现更为均匀的元素混合。此外,相比传统的草酸铵共沉淀法,该法省略了前驱体初烧的步骤,节约了合成的时间和成本。通过X射线衍射（XRD）、扫描电子显微镜（SEM）和电化学测试等检测手段表征了所得样品的晶体结构与电化学性能,研究了两种方法所制备的富锂锰基正极材料的结构、形貌与电化学性能。结果表明,一步草酸共沉淀法合成的富锂材料,拥有更好的结晶性、更大的层间距;材料的颗粒更为均匀和细小。这些晶体结构与形貌上的优势,使得该法制备的富锂材料展现出了更高的放电比容量、更好的循环性能和倍率性能。这些结果均展示了我们所提出的一步草酸共沉淀法的可行性与优势。这种新颖而简便的共沉淀法,可推广于其他层状材料的合成与设计。

英文摘要：

We synthesized layered lithium-rich cathode materials by a novel ethanol-based one-step oxalate coprecipitation method. Using this method, all the elements including lithium could be coprecipitated during the coprecipitation reaction process to realize a homogeneous mixture of lithium and transition metal elements. In addition, compared with the conventional ammonium oxalate coprecipitation method, the precursor preheating process was eliminated, which should decrease reaction time and cost. X- ray diffraction（XRD）, scanning electron microscopy（SEM）, and electrochemical measurements were used to investigate the differences in the crystal structure, morphology and electrochemical performance of samples synthesized using the above two methods. Compared with the samples synthesized by the conventional ammonium oxalate coprecipitation method, samples prepared by our novel one-step oxalate coprecipitation method exhibit higher crystallinity with larger interlayer spacing, and smaller, more homogeneous particles. Such crystal structure and morphology endow the samples prepared by the oxalate coprecipitation method with better discharge capacity, cycle performance and rate performance than those synthesized by the conventional method. The simple, efficient coprecipitation method developed here may provide a new approach to fabricate layered materials for highperformance lithium-ion batteries.