Functionalization of polyvinyl alcohol composite membrane by CoOOH for direct borohydride fuel cells

Abstract A polyvinyl alcohol anion exchange resin composite membrane was functionalized with CoOOH for use in direct borohydride fuel cells (DBFCs) and is detailed in this report. The CoOOH-functionalized membrane has a higher ionic conductivity and a lower borohydride ion permeability than the membrane without CoOOH. The DBFCs with the CoOOH-functionalized membrane achieved better performance, such as a power density peak at 144 mW·cm − 2 at 30 °C, than did those without CoOOH. Such performance improvement is due to CoOOH functionalization, whereby Co species reduce the crossover of the borohydride ion while maintaining high conductivity for hydroxyl species. With the introduction of the Co species, the conductivity-permeability trade-off dilemma in traditional anion exchange membranes is avoided. Therefore, the functionalization of the membrane helps to elucidate the development of anion exchange membrane fuel cells.