Shanghai Jiao Tong University Team in *Science Advances*: "Stream-Reservoir" Type Proton Exchange Membrane Research

A research team from Shanghai Jiao Tong University published a groundbreaking study in Science Advances, developing a short-side-chain perfluorosulfonic acid proton exchange membrane (SSC-PFSA) and successfully constructing a "stream-reservoir" type ion channel structure. This significantly enhances fuel cell performance under high-temperature and low-humidity conditions, providing an innovative solution to the challenge of "high-temperature, low-humidity operation" in the fuel cell industry.

I. Analysis of the "Stream-Reservoir" Structure

Using synchrotron radiation in situ scattering technology, the research team observed the structural evolution of the membrane material during film formation in real time, discovering a previously unseen microstructure:

"Stream": Refers to tiny ion channels with a diameter of approximately 2–3 nm, akin to capillaries, whose core function is to facilitate rapid proton transport, ensuring high efficiency of proton conduction.

"Reservoir": Refers to hydrophilic regions about 10 nm in size, capable of adsorbing and storing large amounts of water, effectively preventing membrane dehydration in high-temperature environments and solving the water management problem under high-temperature, low-humidity conditions.

II. Impressive Performance Data

Compared to traditional Nafion membranes, the SSC-PFSA membrane achieves a qualitative leap in several key metrics, as shown in the table below:

III. Core Reasons for Superior Performance

1. Higher Ion Exchange Capacity: The short-side-chain structure allows for a denser distribution of sulfonic acid groups, effectively enhancing proton conduction capability.
2. Enhanced Mechanical and Thermal Stability: High molecular weight and crystallization behavior strengthen the membrane body, with a glass transition temperature significantly higher than that of traditional membranes.
3. Lower Activation Energy for Proton Transport: The activation energy is 0.069 eV, lower than the 0.084 eV of Nafion membranes, indicating easier proton movement and higher conduction efficiency.
4. Excellent Water Management Capability: The water absorption rate is 93% faster than that of Nafion membranes, effectively balancing moisture to avoid membrane drying or flooding issues.

IV. Broad Application Prospects and Industry Significance

This technology is not only suitable for vehicle fuel cells, but also demonstrates great potential in high-temperature, high-power scenarios such as heavy-duty trucks, drones, and backup power supplies. The research team has developed a single battery with a power density of 1.588 W/cm², reaching the top level of current PFSA-based fuel cells.

The emergence of the SSC-PFSA membrane represents a full-chain breakthrough in the fuel cell field, from "structural design" to "performance realization." Its significance lies in three aspects: first, the "stream-reservoir" model provides a new paradigm for subsequent material design, proving that microstructure determines macro performance; second, in-situ characterization techniques such as synchrotron radiation are key to unlocking the "black box" of the film-forming process; third, the integration of industry, academia, and research will accelerate the transition of laboratory achievements to industrialisation, driving the fuel cell industry toward a new stage of development.