Toward na-ion batteries - Synthesis and characterization of a novel high capacity na ion intercalation material

Buchholz D., Moretti A., Kloepsch R., Nowak S., Siozios V., Winter M., Passerini S.

Abstract

The rapid growth of the worldwide demand of lithium for batteries (LIBs) can possibly lead to a shortage of its reserves. Sodium batteries represent a promising alternative because they enable much higher energy densities than other battery systems, with the exception of LIBs, and are not limited by sodium availability. Herein, we present a novel, Na+ ion intercalation material, Na0.45Ni0.22Co0.11Mn 0.66O2 (space group P63/mmc) synthesized in air by a coprecipitation method followed by a thermal treatment and a water-rinsing step. This material performs a specific capacity of 135 mA h g-1 with a Coulombic efficiency exceeding 99.7%. Upon long-term cycling tests the material shows excellent capacity retention after more than 250 cycles. Such an overall performance, superior to that of presently known sodium-ion cathodes, represents a step further toward the realization of sustainable batteries for efficient stationary energy storage. © 2012 American Chemical Society.