Development of Advanced Li Rich xLi2MO3 (1-x)LiMO2 Composite Cathode for High Capacity Li Ion Batteries
Abstract
Recently, lithium-rich layered oxides have become attractive cathode materials for high torage energy applications. Lithium rich layered oxides materials, represented by the general formula xLi2MnO3(1 - x)LiMO2 in which M is MnNi and Co are of interest for both high-power and high capacity lithium ion cells. In this study, a series of cathode materials with chemical formula of xLi2MnO3(1-x)LiNi1/3Mn1/3Co1/3O2 (x = 0, 0.3, 0.5, 0.7and 1.0) were synthesized by solgel method and investigated for their structure and electrochemical properties. The crystal structure of the sample was examined by X-ray diffraction. It is found that xLi2MnO3(1-x)LiNi1/3Mn1/3Co1/3O2 possessed the composite characteristic of two relatively similar layered structures. Its electrochemical performance is examined with galvanostatic charge/discharge. Increasing Li2MnO3 content tends to stabilize Li rich structure to increase capacity. On the other hand, Li2MnO3 shows an irreversible reaction with a reduced capacity. Accordingly, an optimized result was obtained from 0.5Li2MnO30.5LiNi1/3Mn1/3Co1/3O2 cathode which shows highest electrochemical performance with discharge capacity of 250 mAh/g. However, the capacity fading from these materials was also observed. To understand the behavior of capacity fading for Li-rich cathode materials, Li[Li0.2Mn0.54Ni0.13Co0.13]O2 as a cathode material for Li-ion battery has been carefully investigated. The result shows high initial charge capacity of 327 mAh/g and discharge capacity of 276 mAh/g at 0.05C rate (15mA/g) respectively. After 30 cycles, the discharge capacity decayed to 169 mAh/g. Transmission electron microscopy (TEM) images
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 22, 2016
- Accession Number
- AD1027334
Entities
People
- Chia-chin Chang
- Kuan-zong Fung
- Ying S. Meng
Organizations
- National Cheng Kung University