Effect of ZnO Coating on the Electrochemical Performance of LiMn 1.5 Ni 0.5 O 4 Cathode Material
- PDF / 711,008 Bytes
- 5 Pages / 612 x 792 pts (letter) Page_size
- 82 Downloads / 189 Views
0972-AA06-07
Effect of ZnO Coating on the Electrochemical Performance of LiMn1.5Ni0.5O4 Cathode Material Rahul Singhal1, Maharaj S. Tomar1, Juan G. Burgos2, Arun Kumar2, and Ram S. Katiyar2 1 Physics, University of Puerto Rico, P.O.Box 9016, Mayaguez, 00680, Puerto Rico 2 Physics, University of Puerto Rico, P.O. Box 23343, San Juan, 00931, Puerto Rico Abstract LiMn1.5Ni0.5O4 cathode material was prepared by sol-gel method and annealed at 8500C for 15 hrs. The prepared powder was coated with ZnO by dissolving zinc acetate in methanol and LiMn1.5Ni0.5O4 powder was mixed in this solution followed by the continuous stirring for 4 hr. The LiMn1.5Ni0.5O4 and ZnO coated LiMn1.5Ni0.5O4 powder was characterized using X-ray diffraction, TEM and Raman spectroscopy. The coin cell was fabricated using LiMn1.5Ni0.5O4 and ZnO coated LiMn1.5Ni0.5O4 as cathode materials, LiPF6, dissolved in EC/DMC (1:1 wt ratio) as electrolyte, and Li foil as anode. The cyclic voltammetric and charge-discharge characteristics were carried out for the coin cell using LiMn1.5Ni0.5O4 and ZnO coated LiMn1.5Ni0.5O4 cathode materials. It was found that the ZnO coated LiMn1.5Ni0.5O4 cathode materials showed improved discharge capacity (~146mAh/g) as compared to the pure LiMn1.5Ni0.5O4 (~140mAh/g). The discharge capacity retention after 50 cycles was found to be about 94% and 97% for LiMn1.5Ni0.5O4 and ZnO coated LiMn1.5Ni0.5O4 cathode materials, respectively. Key words: Li ion battery, ZnO coating, charge-discharge, XRD Introduction: During last few years, increasing demand for portable electronic devices, computers, digital camera and eventually, hybrid vehicles has given rise to the increased production of Liion rechargeable batteries to provide the required power sources [1–3]. Since Li-ion batteries have the highest energy density per weight or volume among all available rechargeable batteries, they are considered to be the most suitable candidate for these electronic devices. From last two decades lithium intercalated compounds like LiMn2O4, LiCoO2, and LiFePO4 are being used as cathode materials for the Li ion rechargeable batteries [4-6]. All of these materials suffer severe capacity loss after each charge-discharge cycles. It has already been reported by several researchers that the electrochemical performance of these lithium intercalated compounds can be improved by various metal oxide coatings such as Li2CO3, ZnO, MgO, SiO2, Al2O3, SnO2, ZrO2, SnO2 and other compounds[7-10]. Cho and coworkers [11] have reported that nanoscale coating of cathode materials with metal oxides (Al2O3, ZrO2 etc.) improves the electrochemical performances, by suppressing lattice-constant changes during the first charge. Wang and coworkers [12] found that the surface modification of LiCoO2 with MgO reduced the electrolyte decomposition and hence the cyclic performance of LiCoO2 can be improved by MgO coating. * Contact author: [email protected] (Maharaj S. Tomar) Department of Physics, University of Puerto Rico, Mayaguez, PR-00680 Ph: 1-787-832-4040 (Ext 2011), fax: 1-78
Data Loading...
