Research On Al-Cu-Fe Alloy Cathode Materials For Lithium-ion Batteries

In order to satisfy people’s need for new energy,li-ion battery with high capacity has been extensively studied.Aluminum is easy to form alloys with lithium,including theory capacity of Al4Li9 alloy can reach 2233mAhg-1.In this paper,the lithium storage properties of AlCuFe alloy cathode materials were explored for li-ion batteries.The AlCu Fe alloys were investigated by mechanical alloying method,and the prepared samples were tested for electrochemical performance.For AlCuFe crystalline alloys,we chose Al7Cu2 Fe and Al73Cu5Fe22.As-cast materials were obtained by vacuum melting,and other were made by heat treatment and mechanical milling treatment.The storage capacity of Al7Cu2 Fe material was reduced by heat treatment,and the diancharge capacity of Al73Cu5Fe22 material by heat treatment was highest,which is 87mAhg-1.Aluminum contents of crystalline alloy were more,lithium storage performance was higher.For AlCuFe quasicrystal alloys,we chose Al63Cu25Fe12 and Al64Cu23.5Fe12.5.As-cast materials were obtained by vacuum melting,and further were made by heat treatment and mechanical milling treatment.When the discharge is 0.01 C,the discharge capacity of the Al64Cu23.5Fe12.5 quasicrystal with heat treatment at 800℃ is 177mAhg-1,which is 2 times of the capacity of as-cast alloy.It is 75mAhg-1 higher than discharge capacity of the Al63Cu25Fe12 material after heat treatment.The heat treatment process could improve the storage capacity of quasicrystal alloys.Compared with quasicrystal materials and crystalline materials,discharge capacity of Al64Cu23.5Fe12.5 material by 800℃ heat treatment is highest,cycle performance is best,Single loop voltage-capacity curve did not appear the charging and discharging platform.Quasicrystal structure could store more Li+,lithium storage performance was higher.Mechanical alloying treatment could improve the storage capacity of metallic silicon.With the element powder as raw material,AlCuFe alloy powder was prepared by mechanical alloying.We determined mechanical alloying process: pot powder quality for 5g the ball,added 1.5g of acetone,the speed of 500r/min,milled 20 h,did not appear in the process of ball mill wall sticking phenomenon,During this process,the alloy did not form.The ball milling time were increased to 100 h,the alloy also did not form.