LiCr_(0.1)Ni_(0.45)Mn_(1.45)O_4/Li_4Ti_5O_(12)锂电池容量衰减机理的研究
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摘要
以LiCr_(0.1)Ni_(0.45)Mn_(1.45)O_4为正极,Li_4Ti_5O_(12)为负极组装成新型LiCr_(0.1)Ni_(0.45)Mn_(1.45)O_4/Li_4Ti_5O_(12)电池体系,采用恒流充电模式进行充放电容量和循环性能等电化学性能测试,并通过交流阻抗和循环伏安测试对其容量衰减机理进行研究,结果表明:对于LiCr_(0.1)Ni_(0.45)Mn_(1.45)O_4/Li_4Ti_5O_(12)电池体系,正极活性物质过量越多,循环性能越好;负极-正极活性物质比例N/P为1.1、0.9、0.7的电池体系,25次循环后容量保持率分别为61.4%、70.4%、97.9%;LiCr_(0.1)Ni_(0.45)Mn_(1.45)O_4/Li_4Ti_5O_(12)电池容量衰减的直接原因是电池正负极表面持续生成的CEI膜和SEI膜造成的活性Li~+消耗和电池倍率能力下降。
New battery-system LiCr_(0.1)Ni_(0.45)Mn_(1.45) O_4/Li_4Ti_5O_(12) was prepared by LiCr_(0.1)Ni_(0.45)Mn_(1.45) O_4 positive electrode and Li_4Ti_5O_(12) negative electrode. Electrochemical properties such as charge-discharge capacity and cycle life were tested by constant current charge method. Capacity fading mechanisms were researched by cyclic voltammetry and AC impedance. The results show that LiCr_(0.1)Ni_(0.45)Mn_(1.45) O_4/Li_4Ti_5O_(12) battery-systems with more positive active materials exhibit better cycling performance. After 25 cycles, the capacity retention with three negative-to-positive ratios of 1.1,0.9, 0.7 were 61.4%, 70.4%, 97.9%, respectively. The capacity fading mechanisms of the LiCr_(0.1)Ni_(0.45)Mn_(1.45) O_4/Li_4Ti_5O_(12) were active Li~+ loss in the full-cell system and rate capability degradation, which were induced by continuous SEI films and CEI films formation on top of negative and positive electrode surface.
New battery-system LiCr_(0.1)Ni_(0.45)Mn_(1.45) O_4/Li_4Ti_5O_(12) was prepared by LiCr_(0.1)Ni_(0.45)Mn_(1.45) O_4 positive electrode and Li_4Ti_5O_(12) negative electrode. Electrochemical properties such as charge-discharge capacity and cycle life were tested by constant current charge method. Capacity fading mechanisms were researched by cyclic voltammetry and AC impedance. The results show that LiCr_(0.1)Ni_(0.45)Mn_(1.45) O_4/Li_4Ti_5O_(12) battery-systems with more positive active materials exhibit better cycling performance. After 25 cycles, the capacity retention with three negative-to-positive ratios of 1.1,0.9, 0.7 were 61.4%, 70.4%, 97.9%, respectively. The capacity fading mechanisms of the LiCr_(0.1)Ni_(0.45)Mn_(1.45) O_4/Li_4Ti_5O_(12) were active Li~+ loss in the full-cell system and rate capability degradation, which were induced by continuous SEI films and CEI films formation on top of negative and positive electrode surface.
引文
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[5] ARIYOSHI K, YAMAMOTO S, OHZUKU T. Three-volt lithium-ion battery with Li[Ni1/2Mn3/2]O4and the zero-strain insertion material of Li[Li1/3Ti5/3]O4[J]. Journal of Power Sources, 2003,119/121:959-963.
[6] XIANG H F, ZHANG X, JIN Q Y, et al. Effect of capacity matchup in the LiNi0.5Mn1.5O4/Li4Ti5O12cells[J]. Journal of Power Sources, 2008, 183(1):355-360.
[7] WU H M, BELHAROUAKA I, DENG H, et al. Development of LiNi0.5Mn1.5O4/Li4Ti5O12system with long cycle life[J]. J Electrochem Soc, 2009, 156(12):A1047-A1050.
[8] SHU J. Study of the interface between Li4Ti5O12electrodes and standard electrolyte solutions in 0.0-5.0 V[J]. Electrochemical&Solid State Letters, 2009, 12(2):95-96.
[2] ZHONG G B, WANG Y Y, ZHANG Z C, et al. Effects of Al substitution for Ni and Mn on the electrochemical properties of LiNi0.5Mn1.5O4[J]. Electrochimica Acta, 2011, 56(18):6554-6561.
[3] LIU J, MANTHIRAM A. Understanding the improved electrochemical performances of Fe-substituted 5 V spinel cathode LiMn1.5Ni0.5O4[J]. The Journal of Physical Chemistry C, 2009, 113(33):15073-15079.
[4] JANSEN A N, KAHAIAN A J, KEPLER K D, et al. Development of a high-power lithium-ion battery[J]. Journal of Power Sources,1999, 81/82:902-905.
[5] ARIYOSHI K, YAMAMOTO S, OHZUKU T. Three-volt lithium-ion battery with Li[Ni1/2Mn3/2]O4and the zero-strain insertion material of Li[Li1/3Ti5/3]O4[J]. Journal of Power Sources, 2003,119/121:959-963.
[6] XIANG H F, ZHANG X, JIN Q Y, et al. Effect of capacity matchup in the LiNi0.5Mn1.5O4/Li4Ti5O12cells[J]. Journal of Power Sources, 2008, 183(1):355-360.
[7] WU H M, BELHAROUAKA I, DENG H, et al. Development of LiNi0.5Mn1.5O4/Li4Ti5O12system with long cycle life[J]. J Electrochem Soc, 2009, 156(12):A1047-A1050.
[8] SHU J. Study of the interface between Li4Ti5O12electrodes and standard electrolyte solutions in 0.0-5.0 V[J]. Electrochemical&Solid State Letters, 2009, 12(2):95-96.