Al掺杂高镍锂离子正极材料LiNi_(0.8)Co_(0.2-x)Al_(x)O_(2)的构建与电化学性能研究  

Construction and Electrochemical Performance of Al-doped High Nickel Lithium-ion Cathode Material LiNi_(0.8)Co_(0.2-x)Al_(x)O_(2)

作　　者：孙范 宋洋[1] 邓超[1] Sun Fan;Song Yang;Deng Chao(Harbin Normal University)

机构地区：[1]哈尔滨师范大学

出　　处：《哈尔滨师范大学自然科学学报》2024年第6期83-88,共6页Natural Science Journal of Harbin Normal University

基　　金：研究生创新项目基金(HSDBSCX2023-3)

摘　　要：高镍层状氧化物作为锂离子电池的正极材料,具有很高的能量密度,因此被认为非常有前途.然而,它的循环寿命短和热不稳定性限制了其实际应用.为了克服这些问题,研究人员通过元素掺杂来优化其性能,其中掺杂铝(Al)来提高富镍材料的电化学性能和结构稳定性已取得显著成果.尽管铝掺杂已经被广泛采用,但其在不同含量下对高镍正极材料的具体影响仍未完全了解.为此,研究了一系列铝掺杂的高镍正极材料LiNi_(0.8)Co_(0.2-x)Al_(x)O_(2)(NCA),其中x值分别为0、0.02、0.04、0.05和0.07,掺杂5%的铝被认为是最佳含量,其循环稳定性和晶格结构等都有显著提高.是因为掺杂铝能保持更宽的锂层间距,避免层状结构的崩塌,从而提高了Li+的嵌入嵌出.此外,Al-O键相较于Ni-O或Co-O键更强,能够进一步增强结构稳定性,有效延缓容量和电压的衰减.然而,当铝含量超5%时,会出现一些不良影响,可能是产生LiAlO_(2)和Li5AlO_(4)的杂质相,导致了材料循环稳定性降低.因此,5%的铝认为是掺杂的最佳含量.High-nickel layered oxide is considered very promising as a cathode material for lithium-ion batteries because of its high energy density.However,its short cycle life and thermal instability limit its practical application.To overcome these problems,its performance was optimized through elemental doping,among which aluminum(Al)-doping to improve the electrochemical performance and structural stability of nickel-rich materials has achieved remarkable results.Although aluminum doping has been widely adopted,its specific effects on high-Ni cathode materials at different contents are still not fully understood.For this reason,a series of aluminum-doped high-nickel cathode materials,LiNi_(0.8)Co_(0.2-x)Al_(x)O_(2)(NCA),with xvalues of 0,0.02,0.04,0.05,and 0.07 were investigated in this paper,and 5%aluminum doping was considered to be the optimal content,which resulted in a significant improvement in the cycling stability and lattice structure.Because the doped aluminum can maintain a wider lithium layer spacing and avoid the collapse of the lattice structure,which improves the embedded embedding of Li+.In addition,the Al-O bond is stronger than the Ni-O or Co-O bond,which can further enhance the structural stability and effectively slow down the capacity and voltage degradation.However,when the aluminum content exceeds 5%,some undesirable effects occur,which may be the generation of LiAlO_(2)and Li5AlO_(4)impurity phases,leading to a reduction in the cycling stability of the material.Therefore,5%aluminum is considered to be the optimal level for doping.

关 键 词：锂离子电池 阴极材料 容量保持率 

分 类 号：O61[理学—无机化学]