Chemical Intercalation and De-Intercalation Studies on Multivalent Ion Cathodes

Abstract

As the lithium ion battery technology matures, it becomes apparent that the energy density is more limited by the materials used. Beyond-Li ion battery technology is now garnering more interest, and, as such, the search for new greater energy storage materials is underway. For us we are pursuing multivalent batteries [1] and are investigating new cathode materials, in hopes of discovering and designing new (de)intercalation hosts, or possibly cathodes that hold multivalent cations (Mg2+, Zn2+, Ca2+) by other storage mechanisms as well at high voltages. In particular, oxide cathodes, for example bilayer-V2O5 (BL-V2O5) [2]or alpha-MnO2(hollandite, 2x2 tunnel structure) [3], have been explored for high voltage intercalation. Unfortunately many problems abound, such as poor diffusion of multivalent cations due to strong electrostatic interactions with the oxide lattice. The development of multivalent ion electrolytes is also at its infancy and it is required to exhibit high voltage stability, compatibility with cathode and inactivity towards cell components. Viable electrolytes for this battery task are hard to find, and thus limit our productivity. Nevertheless, the search and evaluation and synthesis will require the means to chemically cycle the materials. A few reagents like di-n-butyl magnesium, di-ethyl zinc have been reported to intercalate Mg2+ and Zn2+ions [4],[5]. In this work and poster, we will discuss and demonstrate a new method of utilizing novel reagents to intercalate multivalent cations into a variety of host materials.