Tin Oxide Modifed LiNi0.8Co0.2O2 Cathode Material for Lithium-ION Batteries

Abstract

Since the commercialization of lithium secondary batteries in the early of 1990s, their development has been rapid. It is a well known fact that lithium ion battery technology’s future depends on mostly improvements in electrode materials. Sol–gel production method is a promising way to prepare electrode materials due to their evident advantages over traditional methods, for example, homogeneous mixing at the atomic or molecular level, lower synthesis temperature, shorter heating time, better crystallinity, uniform particle distribution and smaller particle size at nanometer level. This study focused on the production of a cathode material ‘LiNi0.8Co0.2O2’ improved with a metal oxide ‘SnO2 surface modification’ for obtain improved cycling and better electrochemical performance lithium ion battery. ‘LiNi0.8Co0.2O2’ sub-micron sized powders are produced by using sol-gel production method, with using 3 different chealating agents ( citric acid, oxalic acid, adipic acid), various different calcination temperature (600, 700, 800, 900°C) and durations (5, 10, 15 hours). Following to that, by mechanical mixing and by using sol-gel technique, tin oxide modifcations with different molarities obtained on chosen powders. XRD and SEM analyses performed for obtained bare and modificated powders. These Powders with different characteristics laminated on alumunium foils with an automatic laminaton system and punched as a cathode material to use in coin cells. BET analysis, XRD and SEM studies showed that chealating agent and process parameters effect the powder crystallinity and morphology, and related to these specifications, electrochemical performance is directly effected. Electrochemical results also showed that, SnO2 modificated cathode materials (sol-gel modification) showed better cycle life and capacity retention (above 140mAh/gr) until 50 th cycle due to reducing the electrolyte–cathode interactions.