摘要
通过调节共沉淀制备过程中氨水浓度和pH值控制三元前驱体的成核与长大过程,制备得到团聚态和均一态两种微观结构的Ni0.85Co0.10Mn0.05(OH)2前驱体。两种前驱体的粒度分布,比表面,振实等理化指标接近。烧结后制备LiNi0.85Co0.10Mn0.05O2三元正极材料测试电化学性能表明,两种正极的克容量及倍率性能相近,但具有均一态结构的正极材料1C循环50周后容量保持率达到98.3%,高于团聚态结构正极材料的96.9%循环保持率。d Q·d V-1分析表明,具有均一态结构的正极材料循环前后的氧化还原峰位置和压差稳定,显示了较小的极化损失。进一步通过SEM表征,循环前后具有均一态结构的正极材料断面密实,显示出较高的机械强度,因此在充放电循环过程中颗粒无明显破碎,有较稳定的电极/电解液界面,可改善循环性能。
In this work, the nucleation and crystal growth processes of the precursor can be controlled by adjusting the ammonia concentration and pH value during the co-precipitation processes, and two types of high-nickel Ni0.85Co0.10Mn0.05(OH)2 precursors with different particle structures(agglomerated vs.uniform) are synthesized. The as-synthesized precursors show almost similar physical and chemical properties. After sintering process, the obtained LiNi0.85Co0.10Mn0.05O2 cathodes also showed similar initial charge/discharge capacities and rate performance. However, LiNi0.85Co0.10Mn0.05O2 cathode resulted from the precursor with uniform structure demonstrates better cycling performance(98.3%capacity retention after 50 cycles at 1 C) than that of the cathode with agglomerated structure(96.9%).The LiNi0.85Co0.10Mn0.05O2 cathode with uniform structure shows stable redox peak position and voltage interval after cycle test by d Q·d V-1 analysis, which indicated the lower polarization loss. Further SEM characterization also revealed the suppression of the microcracks that maintain the mechanical integrity of the particles throughout the cycling process along with the establishment of a stable electrode/electrolyte interface to improved cycling stability.
作者
陈龙
张二冬
IQBAL Azhar
李道聪
杨茂萍
夏昕
CHEN Long;ZHANG Erdong;IQBAL Azhar;LI Daocong;YANG Maoping;XIA Xin(Institute of Engineering Research,Hefei Guoxuan High-Tech Power Energy Co.,Ltd.,Hefei 230012,Anhui,China)
出处
《储能科学与技术》
CAS
CSCD
2020年第2期409-414,共6页
Energy Storage Science and Technology
基金
国家重点研发计划项目(2016YFB0100301)。
