Study Of Performance Of Red Phosphorous-based Negative Electrode Materials For Lithium-ion Batteries

With the increasing depletion of the fossil fuels,the environmental pollution of the fossil fuels’ consumption is becoming more and more serious.Therefore,more and more attention is focused on the research of new energy. Lithium ion battery not only has a great application in portable electronic devices,but also in the aerospace, military and other defense also has a huge application prospect.In the several few years, the development of the new generation of electric vehicles(EV) and hybrid electric vehicle(HEV) is attracted more attention.This makes the higher and more stringent requirements of the energy density and the safety performance of the lithium ion battery. There,the development of a new generation of lithium batteries, especially for the development of electrode material is very important. Red phosphorus as anode materials for lithium ion batteries has high specific capacity,whitch can reach 2596mAh/g in theory.But the electrical conductivity of red phosphous is not high,whitch results in poor electrochemical performance.Usually,we use the composites of red phosphous with other materials as the anode of lithium ion battery,whitch is utilized to study its electrochemical performance.In this paper,the red phosphous/Tungsten carbide(P/WC) and red phosphous/peanut shell(PS) are synthesized in three ratio via ball-milling,the composite’s structure is investigated by XRD,SEM and Raman.Then the composites are prepared as the anodes of the lithium ion batteries, its’ electrochemical performance is investigated by Cyclic voltammetry(CV), Electrochemical Impedance Spectroscope(EIS) and long time cycling test.The results shown that the cycle stability is the best in the ratio of 7:3 for the P/WC composite,but its capacity is the lowest,which is 258.43mAh/g after 25 cycles at 0.2A/g current density.For the P/PS composite,the cycle stability and capacity were increased with the increase of PS content in composite materials,the composite of the ratio 3:7 exhibits 774.4mAh/g specific capacity under 0.2A/g current density in 100 cycles.In order to improve the specific capacity and cycle stability of the composite,the composite of the ratio 7:3 both for P/WC and P/PS are composited with graphite via ball-milling,and then the electrochemical performance is investigated.The test results shown that,with the introduction of graphite in the composite,it not only can improve the cycle stability of the anode but also can increase the specific capacity of the composite.But the increasing of the specific capacity with graphite is limited, further increase the content of graphite in the composite,the specific capacity of the anode for composite is not increased.