ultrathin nafion-filled porous membrane for zinc/bromine redox flow batteries - ess energy storage system

In this work, we propose a 16 μm-thick Nafion-
Filled porous film for zinc/Br redox mobile battery (ZBBs).
Through molecular dynamics simulation and dynamic scattering analysis, we have reasonably designed the Nafion solution (PP)separator. A void-
The free Nafion/pp film was successfully prepared using NMP as the solvent of Nafion solution.
Compared with 600 μm, the resulting film shows a smaller area ratio than the resistance-
Thick, commercial SF-
Porous film of 600.
Due to its dense morphology, the Br2 diffusion coefficient of the Nafion/pp film is higher than SF-
600, although there were 37, similar Br2 crosses were produced.
Film thickness is 5 times smaller.
Therefore, the ZBB based on the Nafion/PP film exhibits higher energy efficiency, which indicates that the ion exchange film can be superior to the traditional porous film by reducing the film thickness and has a cheap porous matrix
In the past ten years, people have
Scale energy storage system (ESS)to meet ever-
Changes in energy supply and demand.
ESSs, which provides power storage for renewable energy and its online
The release of demand should be energy
Efficient, safe, reliable and economicaleffective.
In this regard, the redox mobile battery (RFBs)
Considered a promising option for large enterprisesscale ESS.
RFBs are characterized by the spatial separation of energy storage and energy conversion functions, which enables power and energy capabilities to be customized independently.
Since the positive and negative active substances dissolved in the electrolyte are stored in separate tanks, respectively, it can greatly alleviate the safety problems of contact between the two active substances.
According to the redox pairs used, there are many forms of RFB.
Several RFBs were considered for ESS applications, including all vanadium, zinc/Bromo and iron/chromium RFB.
In these RFBs, ZBB is based on its higher energy density (70u2009Whu2009kg)and lower cost.
The electro-chemical reaction of ZBB is the cathode deposition of zinc on the negative electrode and the anode formation of the polybromo phase on the positive electrode during the charging process, as well as the anode dissolution of zinc on the negative electrode and the cathode formation of Br on the positive electrode, as described in the following equation.
In the traditional ZBB structure, the porous membrane placed between the positive and negative poles of the ZBB acts as a barrier for Br crossing, while allowing ion conduction of zinc and Br.
Hundreds of micrometers so far
Thick hydrophilic-
SF-treated porous polyethylene film600 (Asahi Kasei)
Considering the balance between ion conduction and Br cross, the damamic film has been applied in practice;
To prevent Br from crossing through pores, this thick film is used despite the increased membrane resistance.
On the other hand
The porous Nafion film for all vanadium RFBs can also be used for ZBB, as evidenced by Lai, due to its high BR barrier capability. .
They compared Nafion 115 (127u2009μm)
With ZBB's Daramic film, it was found that Nafion 115 has a higher Cullen efficiency of 15%, but the voltage efficiency is reduced by 12% due to its larger membrane resistance.
Therefore, Nafion 115 has not increased significantly in terms of energy efficiency.
In addition to the large film resistance, the high cost of the Nafion film can further prevent its use in ZBB.
In this context, we propose
Filled composite film of porous PP separator based on Nafion Poly and ZBB application.
PP separator widely used in the field of lithium ion battery technology is compatible with ZBBs due to its chemical inertia and mechanical robustness.
The role of PP separator in reducing membrane cost is two-fold;
PP separator is a cost-
Effective substrate because it is a rich commodity and can reduce the use of Nafion materials.
In order to obtain high Br blocking performance, Nafion disaggregation should be immersed into the hole without forming any void.
In this regard, the solvent of the Nafion solution is high for the realization
A high quality Nafion/pp film was reasonably designed using molecular dynamics simulation and dynamic scattering analysis.
In this work, we demonstrate the efficacy of the Nafion/pp film for ZBB with the commercial micropore film SF-600.
Due to the low film thickness of the PP separator, the membrane resistance of the Nafion/PP film is small, so the voltage efficiency is higher.
Due to the tight morphology of the Nafion/pp film, the Br cross can be effectively suppressed even in the case of a thickness of 37.
Five times smaller than SF-600 membrane.
So, the Nafion/pp film-
Energy Efficiency ratio SF based on ZBB-600-based one.
This is the first demonstration of Nafion-with superior performance
The basic membrane of the traditional porous membrane in ZBB.