Towards Na-ion batteries – Synthesis and Characterization of a novel high capacity Na-ion intercalation material

Buchholz D, Moretti A, Klöpsch 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, Na0.45Ni0.22Co0.11Mn0.66O2 (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.