Investigation of the characteristics of a stacked direct borohydride fuel cell for portable applications

The Performance of a Direct Borohydride/Peroxide Fuel Cell Using Graphite Felts as Electrodes

“…Each polarization curve was plotted by taking the average cell voltage with respect to each current density level, as shown in Figure 2b. The maximum power density was approximately 0.24 W·cm −2 at 0.8 V, which was higher than results in other published works [16][17][18]. Because the porosity of graphite felts was higher than that of carbon paper/cloth, the transport of aqueous anolyte/catholyte was enhanced in the DBPFC of this study, resulting in improved performance.…”

“…Raman et al [16] employed stainless-steel blocks with machined flow fields for a six-cell DBPFC stack; the peak power density was 50 mW·cm −2 . Kim et al [17] designed a DBPFC stack with a corrugated flow pattern on the anode and a parallel serpentine pattern on the cathode; the maximum power density of that stack was 183.8 mW·cm −2 . Khadke et al [18] operated a DBPFC with double and single serpentine channels for the anode and cathode, respectively; that stack provided a maximum power density of 180 mW·cm −2 .…”

Developments in direct borohydride fuel cells and remaining challenges

“…Analysing the polarization curves it was found that increasing the flow rate of the oxidant led to small increases in the power density (8.5 and 10.1 mW cm À2 at 10 and 150 cm 3 min À1 , respectively). Kim et al [83], on the other hand, increased the power density of the cell by 21% by increasing the oxidant (air) flow rate from 5 to 10 dm 3 min À1 and keeping a constant fuel flow rate of 0.108 dm 3 min À1 . Clearly, low flow rates (<10 dm 3 min À1 ) will engender high polarizations as a result of oxidant depletion, and are not, therefore, practical.…”

“…Kim et al [83] used a parallel flow field in the anode compartment and a serpentine flow field in the cathode; the anode catalyst was a Zr-based AB 2 -type H 2 storage alloy and the cathode catalyst was 5 wt. % Pt/C.…”

Influences of hydrogen evolution on the cell and stack performances of the direct borohydride fuel cell

“…Ha and co-workers tried to improve stack performance by decrease of hydrogen evolution influence through suitable anode shape design [18] and flow field improvement [19]. We have successfully assembled the panel DBFC stacks using 2 cells or 8 cells to generate 1 W or 4 W of electricity [20].…”