For renewable energy sources such as solar, wind, and hydroelectric to be effectively used in the grid of the future, flexible and scalable energy-storage solutions are necessary to mitigate output fluctuations. Redox-flow batteries (RFBs) were first built in the 1940s2 and are considered a promising large-scale energy-storage technology. A limited number of redox-active materials—mainly metal salts, corrosive halogens, and low-molar-mass organic compounds—have been investigated as active materials, and only a few membrane materials, such as Nafion, have been considered for RFBs. However, for systems that are intended for both domestic and large-scale use, safety and cost must be taken into account as well as energy density and capacity, particularly regarding long-term access to metal resources, which places limits on the lithium-ion-based and vanadium-based RFB development. Here we describe an affordable, safe, and scalable battery system, which uses organic polymers as the charge-storage material in combination with inexpensive dialysis membranes, which separate the anode and the cathode by the retention of the non-metallic, active (macro-molecular) species, and an aqueous sodium chloride solution as the electrolyte. This water- and polymer-based RFB has an energy density of 10 watt hours per litre, current densities of up to 100 milliamperes per square centimetre, and stable long-term cycling capability. The polymer-based RFB we present uses an environmentally benign sodium chloride solution and cheap, commercially available filter membranes instead of highly corrosive acid electrolytes and expensive membrane materials.

Nature (2015) doi:10.1038/nature15746
Received 31 March 2015 Accepted 29 September 2015 Published online 21 October 2015

http://www.nature.com/nature/journal/vaop/ncurrent/full/nature15746.html

对于新型能源（如太阳能、风能等），若想使其高效的并入到电网中，配备大规模储能装置以减轻输出波动是十分必要的。氧化还原液流电池（RFBs）被认为是一种有希望的大规模储能技术，但是目前种类还很少，而且容量和稳定性也较差。Janoschka 等人报道了一种廉价、安全、可大规模应用的 RFB 。这种电池以有机聚合物作为储能材料，并搭配以低成本的透析膜。电池以氯化钠溶液为电解质，能量密度达到 10 瓦特/公斤，单位平方厘米的电流密度达到 100 毫安。这种 RFBs 的一大优势在于应用的是环境友好的电解质材料和膜材料，从而有效避免了酸性电解质对电池的腐蚀作用。（新材料在线整理）