CAJ | 학술논문

采用X射线衍射仪(XRD)、扫描电子显微镜(SEM)、电池性能测试系统研究了多元稀土掺杂锂锰氧正极材料的相结构、形貌,并对其活化性能、循环稳定性能进行了表征.结果表明:采用Pechini法合成多元稀土掺杂LiMn_2O_4样品时,只有将掺杂元素的含量严格控制在一定范围内,所合成的LiMn_2O_4、LiLa0.03Mn1.97O4、LiLa_(0.012)Ce_(0.012)Mn_(1.976)O_4、LiLa_(0.012)Nd_(0.012)Mn_(1.976)O_4、LiCe_(0.012)Nd_(0.012)Mn_(1.976)O_4样品才具有纯尖晶石型LiMn_2O_4结构.当稀土掺杂元素含量较高时,所合成的LiLa0.015Ce0.015Mn1.97O4、LiLa0.015Nd0.015Mn1.97O4、LiCe0.015Nd0.015Mn1.97O4样品由LiMn_2O_4相及微量杂质相CeO_2、Nd_2O_3、CeO_2+Nd_2O_3组成.所有样品呈规则的近球形或球形,其粒径范围为0.5～2.8 μm.适量的稀土元素掺杂将使LiMn_2O_4材料的初始容量减小、充放电效率及循环稳定性能增加,LiCe_(0.012)Nd_(0.012)Mn_(1.976)O_4样品具有较好的综合电化学性能,其初始容量为123.5 mAh/g,经30次循环充放电后的容量为113.2 mAh/g,为相同条件下LiMn_2O_4样品放电容量的1.27倍.
채용X사선연사의(XRD)、소묘전자현미경(SEM)、전지성능측시계통연구료다원희토참잡리맹양정겁재료적상결구、형모,병대기활화성능、순배은정성능진행료표정.결과표명:채용Pechini법합성다원희토참잡LiMn_2O_4양품시,지유장참잡원소적함량엄격공제재일정범위내,소합성적LiMn_2O_4、LiLa0.03Mn1.97O4、LiLa_(0.012)Ce_(0.012)Mn_(1.976)O_4、LiLa_(0.012)Nd_(0.012)Mn_(1.976)O_4、LiCe_(0.012)Nd_(0.012)Mn_(1.976)O_4양품재구유순첨정석형LiMn_2O_4결구.당희토참잡원소함량교고시,소합성적LiLa0.015Ce0.015Mn1.97O4、LiLa0.015Nd0.015Mn1.97O4、LiCe0.015Nd0.015Mn1.97O4양품유LiMn_2O_4상급미량잡질상CeO_2、Nd_2O_3、CeO_2+Nd_2O_3조성.소유양품정규칙적근구형혹구형,기립경범위위0.5～2.8 μm.괄량적희토원소참잡장사LiMn_2O_4재료적초시용량감소、충방전효솔급순배은정성능증가,LiCe_(0.012)Nd_(0.012)Mn_(1.976)O_4양품구유교호적종합전화학성능,기초시용량위123.5 mAh/g,경30차순배충방전후적용량위113.2 mAh/g,위상동조건하LiMn_2O_4양품방전용량적1.27배.
The phase structure, the morphology, activation performance and cycle stability of the rare-earth-doped lithium manganese oxygen cathode materials prepared by Pechini process were investigated by means of X-ray diffraction (XRD), scanning electron microscope (SEM) and battery testing system. The results show that the prepared LiMn_2O_4, LiLa_(0.03)Mn_(1.97)O_4, LiLa0.012Ce0.012Mn_(1.976)O_4, LiLa0.012Nd_(0.012)Mn_(1.976)O_4 and LiCe_(0.012)Nd_(0.012)Mn_(1.976)O_4 samples are composed of single-phase spinel LiMn_2O_4 structure only when the content of rare earth is strictly controlled in a certain range. The LiLa_(0.015)Ce_(0.015)Mn1.97O4, LiLa_(0.015)Nd_(0.015)Mn1.97O4 and LiCe_(0.015)Nd_(0.015)Mn1.97O4 specimens consist of the LiMn_2O_4 and trace CeO_2, Nd_2O_3, CeO_2+Nd_2O_3 phases when the content of the rare earth exceeds the range. The particles of all the specimens are regularly spheroid or near-sphere, and the size of the particles is 0.5-2.8 μm. The initial discharge capacity of the specimens would be decreased, and the ratio of discharge/charge capacity and cyclic stability of the specimens would be increased with the suitable rare earth element doping. The LiCe_(0.012)Nd_(0.012)Mn_(1.976)O_4 cathode materials has good comprehensive electrochemical performances whose initial discharge capacity is 123.5 mAh/g, and whose capacity is 113.2 mAh/g after the 30th cycle, 1.27 times as high as that of LiMn_2O_4 material.