Copper hexacyanoferrate battery electrodes with long cycle life and high power

Abstract

Short-term transients, including those related to wind and solar sources, present challenges to the electrical grid. Stationary energy storage systems that can operate for many cycles, at high power, with high round-trip energy effi ciency, and at low cost are required. Existing energy storage technologies cannot satisfy these requirements. Here we show that crystalline nanoparticles of copper hexacyanoferrate, which has an ultra-low strain open framework structure, can be operated as a battery electrode in inexpensive aqueous electrolytes. After 40,000 deep discharge cycles at a 17 C rate, 83 % of the original capacity of copper hexacyanoferrate is retained. Even at a very high cycling rate of 83 C, two thirds of its maximum discharge capacity is observed. At modest current densities, round-trip energy effi ciencies of 99 % can be achieved. The low-cost, scalable, room-temperature co-precipitation synthesis and excellent electrode performance of copper hexacyanoferrate make it attractive for largescale energy storage systems.

A high-rate and long cycle life aqueous electrolyte battery for grid-scale energy storage

“…Preparation of nanoparticulate CuHCF was based on our recently reported synthesis 12 . Briefly, equal volumes of 40 mM Cu(NO 3 ) 2 (Alfa Aesar) and 20 mM K 3 Fe(CN) 6 (Sigma Aldrich) were combined by simultaneous, dropwise addition into water under vigorous stirring.…”

“…Recently, we developed a family of open-framework nanoparticle materials with the Prussian Blue crystal structure [12][13][14][15] . These materials have an open-framework crystal structure containing large interstitial sites that allows fast insertion and extraction of Na + and/or K + with very little crystallographic lattice strain.…”

A bi-functional device for self-powered electrochromic window and self-rechargeable transparent battery applications

“…Moreover, these cells cannot be used as EC smart windows because the two EC films employed cannot simultaneously change their colours due to opposite biases applied. Recently, Cui and co-workers 30 reported a lithium battery using copper hexacyanoferrate mixed with carbon as the electrode material. A similar electrode material of iron hexacyanochromate has also been used as an anode material for rechargeable batteries 30 .…”

“…Recently, Cui and co-workers 30 reported a lithium battery using copper hexacyanoferrate mixed with carbon as the electrode material. A similar electrode material of iron hexacyanochromate has also been used as an anode material for rechargeable batteries 30 . In brief, all the above-mentioned batteries [27][28][29][30][31] do not utilize the EC function of these EC materials, and their output voltage is relatively low.…”

“…A similar electrode material of iron hexacyanochromate has also been used as an anode material for rechargeable batteries 30 . In brief, all the above-mentioned batteries [27][28][29][30][31] do not utilize the EC function of these EC materials, and their output voltage is relatively low. Like conventional batteries, they are not selfrechargeable and the charging relies on an external power source.…”