Titanium carbide/carbon nanofibers film as flexible gas diffusion layers for passive direct methanol fuel cells

Abstract

Direct methanol fuel cell (DMFC) is considered as one of the next-generation power sources for portable electronic devices. However, the problems of structure and materials of the membrane electrode assembly (MEA) must be resolved if it is applied in flexible electronic devices. The traditional materials of MEA used in DMFC cannot bend and are easy to break. Moreover, the existence of a microporous layer increases the likelihood of separation of the gas diffusion layer (GDL) and catalytic layer. Herein, we develop a simple electrospinning method to prepare flexible titanium carbide/carbon nanofibers (TiC/CNFs) film used as GDL. TiC/CNFs film plays a GDL and a microporous layer dual role. The MEA exhibits enhancing performance and excellent flexibility. The maximum power density of flexible DMFC can reach 20.2 mW/cm 2 , compared with the GDL made of traditional carbon cloth (18.1 mW/cm 2 ), the maximum power density rises by 11.6%. After 50 consecutive bends, the voltage drops less than 10%. This work would promote the flexibility of DMFC.

Flexible All‐Solid‐State Direct Methanol Fuel Cells with High Specific Power Density

“…The lower internal resistance of TiC/CNFs can effectively reduce the charge transfer resistance and enhance the catalytic activity of catalysts, which achieve the purpose of improving catalyst utilization and DMFCs performance. [ 28 ] The greatest power densities of the optimized TiC/CC‐fed DMFC, which were fed with 3 m liquid methanol and 35 wt.% solid methanol, were 21.3 and 20.8 mW cm −2 , respectively. The running life of DMFC will be greatly extended since the energy density of 35 wt.% solid methanol is, in theory, 3.5 times greater than that of 3 m liquid methanol DMFC.…”

Materials, components, assembly and performance of flexible polymer electrolyte membrane fuel cell: A review

“…Additionally, the GDLs prepared with CNT film, CNT powder and binder (Fig. 3b and c) [47] or TiC/CNT film [44] exhibited excellent flexibility and high performance for flexible PEMFCs. Furthermore, nickel foam was used to show excellent performance, which provided more options for fabricating flexible GDL.…”

“…Except the flexible components and the assembly, the storage or supply of fuel [42,43] and oxidant are also essential for the practical application of the flexible PEMFC in flexible devices. To fit the flexible electronic devices, some novel fuel containers with light weight, compact structure, and flexibility have been developed for the flexible PEMFC systems [40,44]. Due to no need for the air supply system, the self-breathing PEMFC shows a great advantage in the flexible devices [45,46].…”

“…The thickness and weight of the flexible PEMFC were declined by using an ultra-thin and flexible GDL composed of carbon nanotubes, leading to the high volume-specific power density (15600 W L − 1 ) and weight-specific power density (9660 W kg − 1 ) [47]. The flexible direct methanol fuel cell (DMFC) containing the flexible GDL based on TiC/carbon nanofibers films exhibited a maximum power density of 20.2 mW cm − 2 and a good stability in the repetitive bending test [44]. Yoo et al implemented a flexible PEMFC with a rubber-like photopolymer-based flow-field plates, which could provide a high power density of 87.1 mW cm − 2 in maximum bending, larger than that in flat position [48].…”

Reduced Graphene Oxide/Carbon Paper for the Anode Diffusion Layer of a Micro Direct Methanol Fuel Cell

“…The physical properties of a DL, as a reactant/product transfer channel and a support structure for the CL, have a very profound effect on the electrochemical reactions in the cell [ 14 , 18 ], such as gas–liquid two-phase mass transfer [ 10 , 12 , 13 , 15 , 17 ], ohmic polarization [ 12 , 13 , 19 ], and methanol crossover [ 10 , 15 , 16 , 17 ]. Graphene is highly conductive and mechanically and chemically stable; thus, it is widely used in DLs in DMFCs [ 10 , 12 , 13 , 15 , 20 ].…”