Al掺杂锰酸锂材料在水系锂离子电池中的循环稳定性  

High electrochemical stability of Al-doped spinel LiMn_(2)O_(4)cathode material for aqueous lithium-ion batteries

作　　者：Ibrahim Al-jawfi 赵佳琦 师萌 康晓红[1] IBRAHIM Al-jawfi;ZHAO Jiaqi;SHI Meng;KANG Xiaohong(Beijing Jiaotong University,Beijing 100044,China)

机构地区：[1]北京交通大学,北京100044

出　　处：《储能科学与技术》2021年第4期1330-1337,共8页Energy Storage Science and Technology

摘　　要：水系锂离子电池具有优良的安全性能和高离子导电性等优点,得到了广泛研究。LiMn_(2)O_(4)材料在水系锂离子电池中较差的循环稳定性使其应用受到限制。为了改善这一缺陷,以乙炔黑为模板,采用简单的高温固相法合成了Al掺杂的LiMn_(2)O_(4)材料(LiMn_(1.9)Al_(0.1)O_(4)),并应用于水系锂离子全电池中。实验结果表明,在0.1 A/g的电流密度下,LiMn2O4材料放电比容量高达125.5 mA·h/g,略高于LiMn_(1.9)Al_(0.1)O_(4)材料的比容量(121.6 mA·h/g)。在0.1 A/g电流密度下,经200次循环LiMn_(1.9)Al_(0.1)O_(4)材料的容量保持率(90%)高于LiMn_(2)O_(4)材料(78%)。将电流密度提升到1 A/g经500次循环后LiMn_(1.9)Al_(0.1)O_(4)和LiMn_(2)O_(4)材料的容量保持率分别为88%和57%。上述结果表明Al掺杂的锰酸锂材料在水系锂离子电池中的循环稳定性以及倍率性能均有明显提高,说明Al的掺杂能显著提升锰酸锂正极材料的结构稳定性,并且能够缓解Mn的溶解和抑制Jahn-Teller效应,改善循环性能。Aqueous Li ion batteries have been extensively studied for their safety and high ionic conductivity.As an important cathode material,LiMn_(2)O_(4) is limited because of its poor cyclic stability in aqueous Li ion batteries.Al-doped LiMn_(2)O_(4) cathode materials were synthesized by a simple high-temperature solid phase method,using acetylene black as the template,and applied to aqueous Li ion batteries.The discharge specific capacity of LiMn_(2)O_(4)(125.5 mA·h·g^(−1))at 0.1A·g^(−1) is slightly higher than that of LiMn1.9Al0.1O4(121.6 mA·h·g^(−1)).The capacity retention of LiMn_(1.9)Al_(0.1)O_(4) cathode materials at 0.1 A·g^(−1) is 90%after 200 cycles,which is higher than that of LiMn2O4(78%).At a high current density of 1 A·g^(−1),the LiMn_(1.9)Al_(0.1)O_(4) sample displays 88%capacity retention after 500 cycles,which is considerably higher than the LiMn_(2)O_(4) sample(57%).These results confirm that Al-doped LiMn_(2)O_(4) cathodes can alleviate the dissolution of Mn,inhibit the Jahn-Teller effect,and improve the cycling performance.

关 键 词：AL掺杂 LIMN2O4 水系锂离子电池 循环稳定性 

分 类 号：TM911[电气工程—电力电子与电力传动]