In Situ Grown ZIF67 Particles on a Glass Fiber Separator: The Performance Booster and Anode Defender for Lithium–Sulfurized Polyacrylonitrile (SPAN) Batteries

Abstract

The sulfurized polyacrylonitrile (SPAN) cathode is the focal point of recent research in lithium−sulfur batteries due to its efficient polysulfide shuttle effect and boosting battery efficiency. However, the SPAN cathode needs to be enhanced to demonstrate more excellent electrochemical performance and kinetic characteristics encouraged by the chemical makeup of the metal−organic frameworks (MOFs) and their effectiveness in the redox reactions of the battery. ZIF67 nanoparticles are grown in situ onto the fiber networks of a high-density glass fiber (GF) separator. They are dynamically activated in a vacuum oven. The open metal sites created after ZIF67 activation can effectively trap anions and improve Li + transport properties. The transference number (t Li + ) was predicted to be 0.49, thereby improving the electrochemical performances of the Li-SPAN battery. The anode and cathode exhibited better compatibility with the separator. The Li//Li symmetrical cells based on the ZIF67@GF separator exhibited low polarization and were stable for up to 600 h. A Li/ZIF67@GF/SPAN full cell also showed a small voltage polarization effect and had a starting capacity of 1590 mAh g −1 at 0.1C rate. The improved high-rate capability (ca. 714 mAh g −1 at 10C) of Li/ZIF@GF/ SPAN cells was better than that of the Li/bare GF/SPAN cells. The long-term cycling performance was improved significantly, with a decay rate of 0.05% per cycle at 2C over 600 cycles and the ability to perform 1000 cycles at a rate of 5C with 75.3% capacity retention. Thus, our findings support that the Li-SPAN cell equipped with a GF separator with in situ grown ZIF67 nanoparticles substantially improved the electrochemical performance.

Suppression of Polysulfides by Carbonized Polyacrylonitrile Modified Polypropylene Janus Separator for Li2S/r-GONR/CNT-Based Li–S Batteries

“…Therefore, interfacial resistances before and after polarization can be estimated by using EIS measurements. The purpose of measuring interfacial resistances is to reduce the error that results from the interface evolution of the Li + ion with the electrolyte during the measurement …”

“…The purpose of measuring interfacial resistances is to reduce the error that results from the interface evolution of the Li + ion with the electrolyte during the measurement. 49 The lithium-ion transference numbers for modified and uncoated PP separators were calculated using the Bruce− Vincent−Ivan equation, 50 as shown in eq 3…”

“…The modified PP Janus separator improved wettability between the electrode and electrolyte interface, helping to reduce the internal resistance, thereby promoting ionic conductivity and increasing discharge capacity. 49 In general, Li 2 S electrodes must overcome a large potential barrier at their first charging cycle at 0.05C in the voltage range of 1.8−3.6 V (vs Li/Li + ). The activation barrier was attributed to the high charge-transfer resistance in the delithiating Li 2 S, which was due to its poor electronic conductivity and low Li +ion diffusivity.…”

“…The increased overpotential in the cells with uncoated PP was caused by ongoing solid electrolyte interface (SEI) regeneration and a severe PS shuttering effect. 49 Cyclic voltametric analyses were conducted at a scan rate of 0.1 mV s −1 in the range of 1.8−2.7 V (vs Li/Li + ), as shown in Figure 7d−f. The CV curves exhibited two reduction peaks; the peak at approximately 2.3 V corresponded to the reduction of S 8 to soluble Li 2 S n (4 ≤ n ≤ 8), whereas the peak at 2.0 V was associated with Li 2 S n reduction (4 ≤ n ≤ 8) to insoluble Li 2 S 2 /Li 2 S. Additionally, the oxidation peak at 2.4 V was mainly associated with the oxidation of Li 2 S 2 /Li 2 S to Li 2 S n (4 ≤ n ≤ 8).…”

Triallyl isocyanurate enabled SPAN-based organosulfur featuring high sulfur & selenium loading for advanced Li/Na–S batteries

“…For example, structural engineering is adopted to construct stable sulfur cathode materials. [11][12][13][14][15] Novel binders, 16,17 membrane modication, 18,19 and electrolyte engineering are proposed to inhibit the dissolution of LiPSs. [20][21][22] Nevertheless, the complete elimination of sulfur dissolution and shuttle effect is still challenging, which is intimately dictated by the parasitic reaction of high-order lithium polysuldes in the conventional S 8 cathode and their intrinsic high solubility in electrolyte.…”