Preparation And Performance Of Aqueous Lithium Ion Battery Anode Materials

To exploit aqueous lithium ion battery with excellent properties will stress on thedevelopment of outstanding anode materials. With this target, lithium intercalationcompounds including LiV₃O₈, LiTi_PO43and composite material coated by carbon wereprepared. Moreover, the electrochemical performances of coated compounds wereinvestigated. Besides, the reasons of capacity fading on cycling were also be analyzed.LiV₃O₈with particle size of600⁸00nm was fabricated by Citric acid sol-gel method.XRD results reveal that the diffraction Peaks are consistent to the previous reports. CVspresent that LiV₃O₈has better electrochemical reversibility at pH=7electrolyte. Besides,results from ARLB indicate that there is no SEI film formed on the surface of the electrodematerials. Charge and discharge performance were tested in different conditions aqueoussolution. The results show that cell have excellent properties at these conditions of thecapacity ratio of positive and negative1:1.2, pH=7,9mol/L LiNO₃aqueous solution. Theinitial discharge capacity of LiV₃O₈electrode is81mAh/g, After40cycles, the dischargecapacity decreases to72.2mAh/g. These results are better than those reported in theliterature.Carbon was coated on the surface of LiV₃O₈. XRD results reveal that the materialhave different Crystal structure by different Calcination temperature. The LiV₃O₈/C can beformed Only at350℃. Charge and discharge test presented that the capacity of LiV₃O₈/Cwas lower than LiV₃O₈, but the LiV₃O₈/C had an enhanced cycle and rate performancecompared with the LiV₃O₈electrode. Such enhancements are due to the presence of thestable carbon coating layer, which effectively suppresses LiV₃O₈dissolution and maintainsthe structural integrity during cycling. The initial discharge capacity of LiV₃O₈/C electrodeis74.1mAh/g, After60cycles, the discharge capacity decreases to76.6mAh/g. Theseresults are better than those reported LiV₃O₈.LiTi_PO43was fabricated by sol-gel method, carbon was coated on the surface ofLiTi_PO43. The NASICON structure was confirmed by XRD. CVs present thatLiTi_PO43/C has a good electrochemical reversibility in LiNO₃aqenous. Charge anddischarge test show that LiTi_PO43/C have excellent properties at these conditions of thecapacity ratio of positive and negative1:1, pH=7in LiNO₃aqenous.The initial dischargecapacity of LiTi_PO43/C electrode is56.1mAh/g, After40cycles, the discharge capacitydecreases to33.9mAh/g. These results are better than those reported LiTi_PO43.