Creating Improved Cathode Materials for Lithium-Ion Batteries

Author:  Emma Wisniewski-Barker
Institution:  Bryn Mawr College

Lithium-ion (Li-ion) batteries are key to the development of Hybrid Electric Vehicles (HEVs) and Plug-in Hybrid Electric Vehicles (PHEVs). One challenge to overcome that will lead to better-working and longer-lasting batteries for more efficient hybrid vehicles is to change and refine the cathode material. The objective of the research was to create a new cathode material that could overcome the constraints associated with the traditional LiCoO2 cathode by reducing or eliminating the amount of costly cobalt and adding a combination of nickel and manganese to the transition metal layer. The compound Li[Ni0.5Mn0.5]O2 has previously been shown to increase the capacity and energy of the battery while still retaining the layered formation of the LiCoO2. The precursor material, which consisted of either nickel cobalt manganese hydroxide or nickel manganese carbonate, was reacted with sodium carbonate in an oven at varying temperatures. The Na[M]O2, with M being the combination of cobalt, nickel, and manganese, underwent an ion exchange in hexanol with an excess of lithium bromide to obtain Li[M]O2. Initial rate tests examining the performance and life of the batteries have demonstrated that this new cathode material operates slightly better than the current baseline material and has the potential to lead to better batteries for HEVs and PHEVs. Further studies must be done to continue to maximize the performance of these materials.

The Journal of Young Investigators is not affiliated with the US Department of Energy. This paper was written by a student intern with the Department of Energy and does not constitute a declarative position of either the Department of Energy or the Journal of Young Investigators.