Synthesis and Electrochemical Properties of Layered LiNi_(1/3)Mn_(1/3)Co_(1/3)O_2 Cathode Material

LiNi_ 1/3 Mn_ 1/3 Co_ 1/3 O_2 cathode material was synthesized by carbonate simultaneous precipitation method. The material was characterized by XRD (X-Ray Diffraction),SEM (Scanning Electron Microscope),differential chronopotentiometry and galvanostatic cycling. XRD results show that all the products synthesized above 800℃ have typical α-NaFeO_2 layered structure. SEM results show that the powders synthesized at 800℃ have a spherical structure composed of small aggregates, whereas the products synthesized above 900℃ have an irregular structure and are fractured. In the voltage range of 2.5～ 4.4V , the LiNi_ 1/3 Mn_ 1/3 Co_ 1/3 O_2 cathode material synthesized at 950℃ has an initial specific discharge capacity of 162mAh·g~ -1 with effective cycling performance. With the increase of the charge-discharge voltage, electrochemical stability was reduced and irreversible capacity loss occurred during the first cycle. The samples synthesized at lower temperatures (800, 850℃ ) exhibited higher specific capacities and slower capacity fading upon cycling than the samples synthesized at higher temperatures (900, 950℃ ), which was due to the structural difference.