The Redox‐Mediated Nickel–Metal Hydride Flow Battery

作者:Páez Teresa; Zhang FeiFei; Muñoz Miguel Ángel; Lubian Lara; Xi Shibo; Sanz Roberto; Wang Qing; Palma Jesús; Ventosa Edgar
来源:Advanced Energy Materials, 2021, 12(1): 2102866.
DOI:10.1002/AENM.202102866

摘要

Each battery technology possesses intrinsic advantages and disadvantages, e.g., nickel–metal hydride (MH) batteries offer relatively high specific energy and power as well as safety, making them the power of choice for hybrid electric vehicles, whereas aqueous organic flow batteries (AORFBs) offer sustainability, simple replacement of their active materials and independent scalability of energy and power, making them very attractive for stationary energy storage. Herein, a new battery technology that merges the above mentioned battery technologies through the use of redox‐mediated reactions is proposed that intrinsically possesses the main features of each separate technology, e.g., high energy density of the solid active materials, easy recyclability, and independent scalability of energy and power. To achieve this, Ni(OH)2 and MHs are confined in the positive and negative reservoirs of an AORFB that employs alkaline solutions of potassium ferrocyanide and a mixture of 2,6‐dihydroxyanthraquinone and 7,8‐dihydroxyphenazine‐2‐sulfonic acid as catholyte and anolyte, respectively. An energy density of 128 Wh L–1 is achieved based on the capacity of the reservoirs leaving ample room for improvement up to the theoretical limit of 378 Wh L–1. This new battery technology opens up new market opportunities never before envisaged, for redox flow batteries, e.g., domestic energy storage and heavy‐duty vehicle transportation.(#br)Active materials from Ni–metal hydride batteries are confined in the external reservoirs of an aqueous organic flow battery (AORFB), storing energy through the use of redox‐mediated reactions. The resulting battery technology possesses high energy density as well as the intrinsic advantages of AORFBs, e.g., easy recyclability and independent scalability of energy and power.