"Manganese hexacyanomanganate open framework as a high-capacity positive electrode material for sodium-ion batteries"

Hyun-Wook Lee: Richard Y. Wang, Mauro Pasta, Seok Woo Lee, Nian Liu & Yi Cui; Nature Communications, 10/14/14.

Additional Authors: Richard Y. Wang, Mauro Pasta, Seok Woo Lee, Nian Liu & Yi Cui

Abstract:

Potential applications of sodium-ion batteries in grid-scale energy storage, portable electronics and electric vehicles have revitalized research interest in these batteries. However, the performance of sodium-ion electrode materials has not been competitive with that of lithium-ion electrode materials. Here we present sodium manganese hexacyanomanganate (Na2MnII[MnII(CN)6]), an open-framework crystal structure material, as a viable positive electrode for sodium-ion batteries. We demonstrate a high discharge capacity of 209 mAh g−1 at C/5 (40 mA g−1) and excellent capacity retention at high rates in a ​propylene carbonate electrolyte. We provide chemical and structural evidence for the unprecedented storage of 50% more sodium cations than previously thought possible during electrochemical cycling. These results represent a step forward in the development of sodium-ion batteries.