Design of a Membraneless Passive Planar Four-Cell Direct Borohydride Fuel Cell

Abstract

The use of noble catalysts and ion exchange membranes make the design of a direct borohydride fuel cell (DBFC) stack complicate and limit its application. Therefore, the development of simple, cost effective construction for DBFC stacks is necessary. In this paper, a passive DBFC stack that consists of four unit cells was designed, fabricated, and tested. The stack eliminated the need for a polyelectrolyte membrane because of the use of a metal phthalocyanine catalyst for oxygen reduction reaction (ORR), which has a high borohydride tolerance. The electrochemical experiments show that the stack can obtain open-circuit-voltage (OCV) of 3.6 V and the maximal power of 400 mW at 1.5 V at ambient temperature. In addition, the DBFC stack was successfully applied to power a radio, which can continuously run for about 3 h on refueling 8 mL 1 M borohydride solution.