摘要
为了进一步提高锂离子电池LiMn_(0.8)Fe_(0.2)PO_(4)正极材料的放电容量和大电流充放电性能,采用固相合成法制备了Na^(+)掺杂的LiMn_(0.8)Fe_(0.2)PO_(4)/C复合材料。通过物理表征和电池测试,研究了Li位Na^(+)掺杂对LiMn_(0.8)Fe_(0.2)PO_(4)晶体结构和充放电性能的影响。结果表明,适量Na^(+)掺杂可增大材料晶胞体积,提高电极反应可逆性,加快Li^(+)扩散速率,从而提升材料的放电容量和倍率性能。Li_(0.97)Na_(0.03)Mn_(0.8)Fe_(0.2)PO_(4)/C复合材料表现出最好的电化学性能,在0.1 C和2 C倍率下的放电容量达到145 mAh·g^(-1)和116 mAh·g^(-1),在1 C倍率下循环100次容量保持率达到94%。为磷酸锰铁锂正极材料的工业应用提供了一种可行的思路。
In order to further improve the discharge capacity and high-current charge/discharge performance of LiMn_(0.8)Fe_(0.2)PO_(4)cathodematerial for lithiumionbatteries,Na^(+)-dopedLiMn_(0.8)Fe_(0.2)PO_(4)/Ccompositeswerepreparedbysolid-state synthesis.The effects of Na+-doping at the Li site on the crystal structure and charge/discharge performance of LiMn_(0.8)Fe_(0.2)PO_(4)were investigated by physical characterizations and battery tests.The results show that the appropriate doping of Na^(+)can increase the cell volume,improve the reversibility of electrode reaction,accelerate the diffusion rate of Li^(+),and thus improve the discharge capacity and rate capability of LiMn_(0.8)Fe_(0.2)PO_(4).The Li_(0.97)Na_(0.03)Mn_(0.8)Fe_(0.2)PO_(4)/C composite material reveals the best electrochemical activity.It gives discharge capacities of 145 mAh·g^(-1) and 116 mAh·g^(-1) at 0.1 C and 2 C,respectively,along with a capacity retention of 94%over 100 cycles at 1 C.The research provides a feasible idea for the industrial application of LiMn1-xFexPO4 cathode materials.
作者
张宇
刘壮
王浩
王飞
Zhang Yu;Liu Zhuang;Wang Hao;Wang Fei(Huaibei Normal University,Huaibei 235000,China)
出处
《廊坊师范学院学报（自然科学版）》
2024年第4期103-109,共7页
Journal of Langfang Normal University(Natural Science Edition)
基金
安徽省自然科学基金(2008085MB34)
国家级大学生创新创业项目(202310373002)。
