Synthesis and optimization of nanosized energy storage cathodic materials for lithium batteries

Abstract

For four decades, lithium-ion batteries (LIBs) have been amongst the most promising rechargeable batteries for power electronic devices such as cellular phones, laptop computers, digital cameras. Great research efforts impel improving Li-ion battery (LIB) technology, especially the performance of positive electrodes (cathodes) to meet the ever-increasing demands for energy storage to be used in new and high-powered applications like electric vehicles (EVs) and hybrid electric vehicles (HEVs). Spinel LiMn2O4 with its theoretical specific capacity of 148 mAh/g is one of lithium manganese oxide-based materials that has been attracting much attention as an ideal cathode material. This ideal virtue comes from its low toxicity, low cost, easy fabrication, high natural abundance of Mn, high acceptability of environmental impact and good thermal stability. Besides its open three-dimensional (3D) crystal structure which facilitates and improves Li+ diffusion through vacant octahedral and tetrahedral interstitial sites. However, LiMn2O4 suffers from poor cycle stability due to dissolution of Mn and JT-distortion and insufficient rate capability due to its low electrical conductivity. In this work high performance spinel LiMn2O4 with good crystalline structure, rate performance and cycle stability was synthesized in a simple one step precipitation method using oxalic acid as a precipitating agent. This facile method does not require expensive and sophisticated laboratory equipments and extraordinary experimental circumstances, therefore it is fairly financially savvy, as well as time consuming and easily scalable for mass production. The good morphological properties of as prepared LiMn2O4 produced from this precipitation method improved its electrochemical properties. This is because it significantly promotes fast