| Summary: | 碩士 === 國立中央大學 === 化學工程與材料工程研究所 === 95 === In order to shorten process time, reduce synthesis cost, and prepare high performance cathode materials, layered LiNi1/3Mn1/3Co1/3O2 powders were synthesized by two methods, respectively, one is the solution combustion process with hexamethylenetetramine as a fuel and the other is the microwave method followed by short duration high temperature calcination.
After determining optimal preparation conditions, cathode materials synthesized under these conditions and surface treated separately with different metal oxides to enhance cycle stability using a simple mechano-thermal coating procedure.
The powders prepared by solution combustion and microwave methods generated a discharge capacity of 179 mAh/g and 183 mAh/g, respectively, at a 0.2 C-rate between 4.6 and 2.5 V in the first cycle. The structure and morphology of the bare and the surface modified LiNi1/3Mn1/3Co1/3O2 samples have been characterized with XRD, FE-SEM, DLS, TEM, EDS, and DSC techniques.
Electrochemical studies revealed that both methods needed only a third of the process time to synthesize a LiNi1/3Mn1/3Co1/3O2 cathode compared to a conventional co-precipitation route. After surface modification, all the
LiNi1/3Mn1/3Co1/3O2 powders coated with Al2O3 have showed improved cyclabiliy, indicating that coating materials can stabilize the cathode structure by suppressing characteristic structural phase transitions. Moreover, the
mechano-thermal coating process is a simple, inexpensive, environmentally benign and commercially viable for producing high-cycling LiNi1/3Mn1/3Co1/3O2 cathode materials.
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