(1. 湖南有色金屬研究院，長沙 410015；
2. 湖南美特新材料科技有限公司，長沙 410200)
摘 要: 將Ni0.5Co0.2Mn0.3(OH)2前驅(qū)體、碳酸鋰與H3BO3按一定配比高效混合，采用固相燒結(jié)法制備高壓實密度LiNi0.5Co0.2Mn0.3O2粉體正極材料，探討H3BO3添加量對正極材料物理性能、極片壓實密度及電化學性能的影響。使用X射線衍射(XRD)和掃描電鏡(SEM)表征材料的物理性能，將正極材料制作成軟包裝全電池，并對其電化學性能進行測試。結(jié)果表明：H3BO3具有助熔作用；能增加一次粉體正極材料顆粒的粒徑，并提高顆粒致密度，對正極材料的晶體結(jié)構(gòu)沒有影響，但對正極材料粒徑、pH、比表面積及振實密度等產(chǎn)生影響。將H3BO3添加量為0.6%(質(zhì)量分數(shù))時制備的LiNi0.5Co0.2Mn0.3O2正極材料制成正極片后，其極限壓實密度最高達到3.9 g/cm3；與采用常規(guī)LiNi0.5Co0.2Mn0.3O2正極材料制成的正極片(壓實密度≤3.5 g/cm3)相比，其體積能量密度提高約11.4%；0.5C首次放電比容量為153.64 (mA·h)/g，1C循環(huán)首次放電比容量為152.22 (mA·h)/g，100次循環(huán)容量保持率為96.99%，其綜合電化學性能優(yōu)于常規(guī)LiNi0.5Co0.2Mn0.3O2正極材料的。
關(guān)鍵字: 鋰離子電池；LiNi0.5Co0.2Mn0.3O2；壓實密度；H3BO3；助熔作用
（1. Hunan Research Institute for Nonferrous Metals, Changsha 410015, China;
2. Hunan Metal New Materials Technology Co., Ltd., Changsha 410200, China）
Abstract:LiNi0.5Co0.2Mn0.3O2 cathode material with high compacted density was synthesized through solid-state sintering method using LiNi0.5Co0.2Mn0.3O2 precursor, lithium carbonate and H3BO3 at a certain proportion as raw materials. The effects of H3BO3 addition on the physical properties, compacted density and electrochemical properties of the cathode material were studied. The physical properties were investigated by X-ray diffractometry (XRD) and scanning electron microscopy (SEM). The flexible package batteries were fabricated to inspect the electrochemical properties. The results show that H3BO3 with fluxing action can refine the primary particle size and improve the compact level of the particles. H3BO3 has no influence on the crystal structure, but has impact on the particle size, pH, specific surface area and the tap density. The electrochemical property of LiNi0.5Co0.2Mn0.3O2 with 0.6% H3BO3 (mass fraction) is better than that of normal LiNi0.5Co0.2Mn0.3O2 cathode material. The operating limiting compacted density of the electrode increases from 3.5 g/cm3 to 3.9 g/cm3, so that the volume energy density improves by about 11.4%. The first discharge specific capacity is 153.64 (mA？h)/g and 152.22 (mA？h)/gat 0.5C and 1C, respectively. The discharge capacity retention is 96.99% after 100 cycles.
Key words: lithium ion battery; LiNi0.5Co0.2Mn0.3O2; compacted density; H3BO3; fluxing action
