摘要
本文采用球形Al/Co部分取代α型Ni(OH)2为前驱体成功制备了锂离子电池正极材料LiNi0.8Co0.15Al0.05O2。首先采用氢氧化钠与碳酸钠为沉淀剂合成出Al/Co部分取代α型Ni(OH)2,然后将之与LiOH·H2O混合,最后在氧气气氛中不同温度下热处理8h,即可得到球形LiNi0.8Co0.15Al0.05O2材料。X射线衍射结果表明,LiNi0.8Co0.15Al0.05O2材料为α-NaFeO2相。扫描电镜结果表明,材料颗粒形貌为球形。热重分析结果表明合成LiNi0.8Co0.15Al0.05O2的主反应温度在700～750℃之间。振实密度测试结果表明,750℃下制备的LiNi0.8Co0.15Al0.05O2材料可达2.2g·cm-3。恒流充放电结果表明,该材料在0.5mA·cm-2电流密度下,在3.0～4.3V间的首次充电容量可达210.3mAh·g-1,首次放电容量为179.7mAh·g-1,充放电效率为85.4%。与采用以β-Ni0.85Co0.15(OH)2为前驱体合成的LiNi0.85Co0.15O2和Al掺杂的LiNi0.8Co0.15Al0.05O2相比,尽管其首次放电容量与放电效率都有所降低,但循环性能有所提高,50周期后容量仍为初始容量的89.5%。研究表明,以球形Al/Co部分取代α型Ni(OH)2作为前驱体为球形氧化镍钴铝锂材料的制备提供了一条新的途径。
A LiNi0.8Co0.15Al0.05O2 cathode material was successfully synthesized by a spherical Co/Al-substituted α-Ni（OH）2 as the precursor and its electrochemical performance was investigated. This precursor was prepared by a co-precipitation method by a NaOH solution containing Na2CO3 as the precipitator, then heated with LiOH·H2O at different temperatures for 8 h in an oxygen atmosphere to form LiNi0.8Co0.15Al0.05O2. XRD results showed that the LiNi0.8Co0.15Al0.05O2 had an α-NaFeO2 phase. SEM results indicated that the particles had spherical morphology. TG and DSC results revealed that the suitable formation temperature of the LiNi0.8Co0.15Al0.05O2 material was in the range between 700 and 750 ℃. The tap density result showed that the LiNi0.8Co0.15Al0.05O2 material sintered at 750 ℃ was up to 2.2 g·cm-3. Its initial charge-discharge capacity was 210.3 and 179.7 mAh·g-1 at 0.5 mA·g-1, respectively. Although the initial discharge capacity and coulombic efficiency of the LiNi0.8Co0.15Al0.05O2 cathode prepared by α-Ni0.85Co0.15Al0.05（OH）2 as the precursor was lower than those of the LiNi0.85Co0.15O2 and LiNi0.8Co0.15Al0.05O2 cathodes prepared by β-Ni0.85Co0.15（OH）2 as the precursor, its cyclic behavior was improved, where its discharge capacity still reached 89.5% of its initial one. It suggested that this work provided a new method to prepare LiNi0.8Co0.15Al0.05O2 cathode material by α-Ni0.85Co0.15Al0.05（OH）2 as the precursor.
出处
《无机化学学报》
SCIE
CAS
CSCD
北大核心
2010年第2期190-196,共7页
Chinese Journal of Inorganic Chemistry
基金
国家自然科学基金(No.20873072)
天津市应用基础及前沿课题重点项目(No.07JCZDJC02700)资助
关键词
锂离子电池
LiNi0.8Co0.15Al0.05O2正极材料
球形α型氢氧化物
前驱体
电化学性能
A LiNi0.8Co0.15Al0.05O2 cathode material was successfully synthesized by a spherical Co/Al-substituted α-Ni（OH）2 as the precursor and its electrochemical performance was investigated. This precursor was prepared by a co-precipitation method by a NaOH solution containing Na2CO3 as the precipitator, then heated with LiOH·H2O at different temperatures for 8 h in an oxygen atmosphere to form LiNi0.8Co0.15Al0.05O2. XRD results showed that the LiNi0.8Co0.15Al0.05O2 had an α-NaFeO2 phase. SEM results indicated that the particles had spherical morphology. TG and DSC results revealed that the suitable formation temperature of the LiNi0.8Co0.15Al0.05O2 material was in the range between 700 and 750 ℃. The tap density result showed that the LiNi0.8Co0.15Al0.05O2 material sintered at 750 ℃ was up to 2.2 g·cm-3. Its initial charge-discharge capacity was 210.3 and 179.7 mAh·g-1 at 0.5 mA·g-1, respectively. Although the initial discharge capacity and coulombic efficiency of the LiNi0.8Co0.15Al0.05O2 cathode prepared by α-Ni0.85Co0.15Al0.05（OH）2 as the precursor was lower than those of the LiNi0.85Co0.15O2 and LiNi0.8Co0.15Al0.05O2 cathodes prepared by β-Ni0.85Co0.15（OH）2 as the precursor, its cyclic behavior was improved, where its discharge capacity still reached 89.5% of its initial one. It suggested that this work provided a new method to prepare LiNi0.8Co0.15Al0.05O2 cathode material by α-Ni0.85Co0.15Al0.05（OH）2 as the precursor.
