Full open-framework batteries for stationary energy storage

Abstract

New types of energy storage are needed in conjunction with the deployment of renewable energy sources and their integration with the electrical grid. We have recently introduced a family of cathodes involving the reversible insertion of cations into materials with the Prussian Blue open-framework crystal structure. Here we report a newly developed manganese hexacyanomanganate open-framework anode that has the same crystal structure. By combining it with the previously reported copper hexacyanoferrate cathode we demonstrate a safe, fast, inexpensive, long-cycle life aqueous electrolyte battery, which involves the insertion of sodium ions. This high rate, high efficiency cell shows a 96.7% round trip energy efficiency when cycled at a 5C rate and an 84.2% energy efficiency at a 50C rate. There is no measurable capacity loss after 1,000 deep-discharge cycles. Bulk quantities of the electrode materials can be produced by a room temperature chemical synthesis from earth-abundant precursors.

A thermogravimetric study of thermal dehydration of copper hexacyanoferrate by means of model-free kinetic analysis

“…TG-MS curves for x = 0.0 in N 2 and for x = 1.0 in air and N 2 are given in the SI. The curves are similar to those recorded in N 2 by Pasta et al [2]. A well-defined first mass loss step associated with the removal of water is observed in the temperature region up to *130°C.…”

“…For the mass loss steps above *180°C, the MS measurements show strong signals from m/z 52 (CN) 2 and m/z 44 (CO 2 ). The mass gain at *220°C is attributable to a backstroke effect at the beginning of a rapid exothermic combustion and is accompanied by a strong signal from m/z 44 (CO 2 ).…”

“…Water-based systems with Prussian blue analogues (PBAs), e.g. copper hexacyanoferrate (CuHCF), as electrodes exhibit a number of merits; they can be synthesized in large quantities from cheap precursors and show long cycle lives, fast kinetics, high power operations, and good energy efficiencies [2]. There has been a burgeoning interest in Prussian blue (PB) and PBA compounds in the last decades for other applications as well; hydrogen storage [3], electrocatalysis [4], and charge storage [5], are a few examples from a large variety of fields.…”

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

“…1a) and is 171 mAh g À 1 in the case of Prussian Blue (FeHCFe). Recently, we and others have utilized PBAs as battery electrodes with excellent cycle life and rate performance in both aqueous and organic electrolytes for NIBs [11][12][13][23][24][25][26][27][28][29] .…”

Ti-substituted tunnel-type Na0.44MnO2 oxide as a negative electrode for aqueous sodium-ion batteries

“…In particular, aqueous sodium-ion batteries have attracted great interest in terms of their safety, low-cost and high-rate capability [21][22][23][24][25][26][27][28] . Many interesting electrode materials have been studied in aqueous electrolytes.…”