NaAlO_(2)包覆LiNi_(0.4)Co_(0.2)Mn_(0.4)O_(2)材料用于提高锂离子电池正极材料电化学性能

Improving electrochemical performance of cathode LiNi_(0.4)Co_(0.2)Mn_(0.4)O_(2) for Li-ion batteries by coating NaAlO_(2)

锂离子三元正极材料由于其结合了镍酸锂、钴酸锂、和锰酸锂材料的特性一直是人们研究的热点,但不同比例的三元材料有着不同的优势和缺陷。LiNi_(0.4)Co_(0.2)Mn_(0.4)O_(2)材料虽倍率性能较好但是循环性能比较差,不能满足人们对日常生活更高的需求。因此提高材料的电化学性能一直是学者们所追求的目标,掺杂和包覆是两种对材料进行改性的有效手段。通过共沉淀法制得LiNi_(0.4)Co_(0.2)Mn_(0.4)O_(2)并用NaAlO_(2)对LiNi_(0.4)Co_(0.2)Mn_(0.4)O_(2)进行包覆改性。通过一系列表征手段和电化学测试,证明了NaAlO_(2)包覆LiNi_(0.4)Co_(0.2)Mn_(0.4)O_(2)材料作为一种方法能明显提高LiNi_(0.4)Co_(0.2)Mn_(0.4)O_(2)的循环性能和倍率性能,并对电化学性能改善的原因进行了简要地分析。

The lithium ion ternary anode material has always been a hotspot because of the reason that it combines the characters of the LiNi_(0.4)Co_(0.2)Mn_(0.4)O_(2) and LiMnO_(2).Nevertheless materials of the different ratios have different advantages and defects.Material of LiNi_(0.4)Co_(0.2)Mn_(0.4)O_(2) has a better magnification performance with the relatively poor cycle performance,which is not satisfied with higher demand for daily lives.The electrochemical properties of the material have always been the goal pursued by scholars,who have been making some modified methods such as coating and doping strategies.In this paper,the material of LiNi_(0.4)Co_(0.2)Mn_(0.4)O_(2) is prepared by co-precipitation method and modified with NaAlO_(2),and the NaAlO_(2) coating as a strategy can significantly increase the cycle performance of LiNi_(0.4)Co_(0.2)Mn_(0.4)O_(2) by a series of characteristic means and electrochemical tests.The magnification performance and the reasons for improvement in electrochemical performance have been briefly analyzed.