Lin J, Wang P, Bin J, Wang L. Achieving 1060 mW cm
-2 with 0.6 mg cm
-2 Pt Loading Based on Imidazole-Riched Semi-Interpenetrating Proton Exchange Membrane at High-Temperature Fuel Cells.
SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024:e2311767. [PMID:
38369969 DOI:
10.1002/smll.202311767]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2023] [Revised: 01/24/2024] [Indexed: 02/20/2024]
Abstract
Enhancing phosphoric acid (PA) doping in polybenzimidazole (PBI) membranes is crucial for improving the performance of high-temperature proton exchange membrane fuel cells (HT-PEMFCs). However, excessive PA uptake often leads to drawbacks such as PA loss and compromised mechanical properties when surpassing PA capacity of PBI basic functionality. Herein, a new strategy that integrates high PA uptake, mechanical strength, and acid retention is proposed by embedding linear PBI chains into a crosslinked poly(N-vinylimidazole) (PVIm) backbone via in-situ polymerization. The imidazole (Im)-riched semi-interpenetrating polymer network (sIPN) membrane with high-density nitrogen moieties, significantly enhancing the PA doping degree to 380% shows an excellent conductivity (0.108 S cm-1 ). Meanwhile, the crosslinking structure in the sIPN membrane ensures adequate mechanical properties, low hydrogen permeability, and a relatively low swelling ratio. As a result, the single cell based on the membrane achieves the highest power density of 1060 mW cm-2 with a low Pt loading (0.6 mg cm-2 ) up to now and exhibits excellent fuel cell stability.
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