Recent Development of Polymer Electrolyte Membranes for Fuel Cells

Abstract

Membranes with Proton-Conducting Polymer Components 2793 4. Nonfluorinated Acid Ionomer Membranes 2793 4.1. Poly(arylene ether)-Based Membranes 2793 4.1.1. Modification of SPEEK Membrane 2793 4.1.2. Poly(arylene ether)s with Cross-Linkable Groups 2794 4.1.3. Poly(arylene ether)s with Pendant Sulfonated Groups or Side-Chains 2799 4.1.4. Poly(arylene ether)s with Backbones Containing Heteroatoms Such as F, N, S, and P 2800 4.1.5. Multiblock Copoly(arylene ether)s Synthesized by the Coupling Reaction of Hydrophilic and Hydrophobic Macromonomers 2803 4.2. Polyimide-Based Membranes 2804 4.2.1. SPIs Based on NTDA 2804 4.2.2. SPIs based on BNTDA 2806 4.2.3. SPIs Based on Other Dianhydrides 2807 4.3. Hydrocarbon Polymer with Aliphatic Main-Chain-Based Membranes 2807 4.4. Glass Membranes 2809 5. Polybenzimidazole/H 3 PO 4 Membranes 2809 5.1. Modifications to mPBI 2810 5.1.1. Optimizations of Preparation and Operation of Acid-Doped mPBI System 2810 5.1.2. Modified mPBI/H 3

Nanotechnology for environmentally sustainable electromobility

“…Figure 2 presents the material lifecycle attributes of reviewed anode nanomaterials, as well as graphite. Graphite is an abundant material 47 , and its extraction or synthesis has relatively low environmental impact 50,51 . Today, it also requires little energy during its production 22 and allows for batteries with good cyclability 47 and high energy efficiency 52,53 .…”

“…Alternative carbon nanostructures with higher theoretical energy densities are under investigation 34 , but neither carbon nanotubes nor graphene have been found to be technically feasible because they have too many side-reactions 55 . Carbon nanotubes and graphene also exhibit more environmentally intensive 50,51 profiles and, like other carbon 7 nanostructures, their handling requires more precaution 56 than graphite 57 . The current carbon nanotube synthesis routes are energy intensive [58][59][60] .…”

Carbon-Based Metal-Free Electrocatalysis for Energy Conversion, Energy Storage, and Environmental Protection

“…In their further evaluation in anion-exchange membrane fuel cells (AEMFCs), the VA-NCNT and Pt/C electrodes exhibited a current density of 11 and 38 mA cm −2 , respectively, at 0.7 V, along with a corresponding maximum power density of 37.3 and 61.7 mW cm −2 . Whereas the majority of recent studies on carbon nanostructured metal-free electrocatalysts focus on ORR reactions in alkaline electrolytes, fuel cells that operate with acidic electrolytes, particularly polymer electrolyte membrane fuel cells (PEMFC) [14,15], can have a more significant economic impact. Therefore, the development of effective metal-free carbon-based catalysts for acidic electrolytes is important, though still challenging [16,[145][146][147][148][149][150].…”

“…Because ORR, OER, and HER have been reviewed in several previously published articles [4,[10][11][12], the focus in this review will be on recent advances and new reactions (e.g., CO 2 RR, multifunctional electrocatalysis). A critical overview of efficient methods for developing carbon-based metal-free catalysts for various energy conversion/storage and environmental protection devices, including ORR in fuel cells [13][14][15][16][17], ORR and OER in metal-air batteries [18][19][20][21][22][23][24][25][26][27][28], OER and HER in water-splitting units [29][30][31], I − /I 3− reduction in dye-sensitized solar cells [32][33][34][35], and CO 2 RR in Li-CO 2 batteries [36][37][38][39][40][41][42] will then be provided. Finally, perspectives and challenges in this fast-growing and significant field are outlined.…”

To immobilize polyethylene glycol-borate ester/lithium fluoride in graphene oxide/poly(vinyl alcohol) for synthesizing new polymer electrolyte membrane of lithium-ion batteries

“…Polymer electrolyte membranes (PEMs) are permeable membranes for the electrolyte ions flowing between a battery's anode and cathode [1][2][3][4]. They can serve both as ionic conductors of lithium-ions (Li + ) and separators with high safety, low cost and good performance when assembled into lithium-ion batteries.…”