LiMn2O4 spinel oxide has been surface/chemically modified with LixCoO2, LiNi0.5Co0.5O2, Al2O3, and MgO using a chemical processing procedure followed by heat-treatment at 300-800°C. The surface/chemically modified samples show much better capacity retention at both 25 and 60°C than does the unmodified LiMn2O4 (41% fade in 100 cycles at 60°C). Among the various compositions investigated, the LiNi0.5Co0.5O2-modified sample shows superior capacity retention with only 2.8% fade in 100 cycles at 60°C with around 110 mAh/g. The Al2O3-modified sample shows a higher capacity of 130 mAh/g, but with a faster fade (16% in 100 cycles at 60°C). The Li0.75CoO2-modified sample shows the best combination of capacity (124 mAh/g) and retention (8% fade in 100 cycles at 60°C). The modified samples also exhibit better capacity retention after aging at 55°C at 60-70% depth of discharge.
ASJC Scopus subject areas
- Chemical Engineering(all)
- Materials Science(all)
- Physical and Theoretical Chemistry
- Electrical and Electronic Engineering