CAJ | 학술논문

利用琥珀酸为鳌合剂的湿化学法成功合成了一系列锂离子电池正极材料LiNi1/3Mn1/3Co1/3O2,在合成过程中改变琥珀酸与金属离子摩尔比(R)并研究了这一参数对合成LiNi1/3Mn1/3Co1/3O2材料物理及电化学性质的影响.采用热重、X射线衍射、Rietveld精修、扫描电镜以及超导量子干涉仪对反应机理、材料的结构、形貌以及磁学性质进行了详细表征.得到最佧合成条件为R=1,此时LiNi1/3Mn1/3Co1/3O2的阳离子混排度最低.此外,通过Rietveld精修得到该材料阳离子混排度的结果与通过磁学方法得到的结果定帚相符,如对于在R=1条件下合成的样品,Rietveld精修结果显示其阳离子混排度为1.85%,而超导最子干涉仪的测试结果为1.80%.当充放电区间为3.0-4.3 V,电流密度为0.2C(1C=160 mA·g-1)时,该样晶的首次放电容量为161 mAh·g-1,库仑效率为93.1%,经过50次循环后,容量保持率可达91.3%.
이용호박산위오합제적습화학법성공합성료일계렬리리자전지정겁재료LiNi1/3Mn1/3Co1/3O2,재합성과정중개변호박산여금속리자마이비(R)병연구료저일삼수대합성LiNi1/3Mn1/3Co1/3O2재료물리급전화학성질적영향.채용열중、X사선연사、Rietveld정수、소묘전경이급초도양자간섭의대반응궤리、재료적결구、형모이급자학성질진행료상세표정.득도최카합성조건위R=1,차시LiNi1/3Mn1/3Co1/3O2적양리자혼배도최저.차외,통과Rietveld정수득도해재료양리자혼배도적결과여통과자학방법득도적결과정추상부,여대우재R=1조건하합성적양품,Rietveld정수결과현시기양리자혼배도위1.85%,이초도최자간섭의적측시결과위1.80%.당충방전구간위3.0-4.3 V,전류밀도위0.2C(1C=160 mA·g-1)시,해양정적수차방전용량위161 mAh·g-1,고륜효솔위93.1%,경과50차순배후,용량보지솔가체91.3%.
A series of cathode materials LiNi1/3Mn1/3Co1/3O2 for lithium-ion batteries were successfully synthesized using succinic acid as a chelating agent by a wet-chemical method. We varied the succinic acid to metal-ion molar ratios (R) and investigated the effect of this parameter on the physical and electrochemical properties of the prepared LiNi1/3Mn1/3Co1/3O2. The reaction mechanism, structural, morphological, and magnetic properties of the powders were characterized in detail by thermogravimetry (TG), X-ray diffraction (XRD), Rietveld refinement, scanning electron microscopy (SEM), and superconducting quantum interface device (SQUID). We determine that the optimum conditions for the synthesis of LiNi1/3Mn1/3Co1/3O2 assisted with succinic acid is R=1, at the lowest amount of cation mixing. In addition, measurement of the magnetic properties revealed a concentration of Ni on the 3b Wyckoff site of the lithium-ions in good agreement with the results from the Rietveld refinement on the XRD spectra. For LiNi1/3Mn1/3Co1/3O2 (R=1), the Rietveld refinement showed that cation mixing in this sample was 1.85%, which is in quantitative agreement with that from the SQUID result (1.80%). It delivered an initial discharge capacity of 161 mAh·g-1 at a current rate of 0.2C (1C=16O mA·g-1) and at a cut-off voltage of 3.0-4.3 V with acoulombic efficiency of 93.1% and its capacity retention was 91.3% after 50 cycles.