Porous Polymer Electrolyte Research Articles

High performance gel polymer electrolyte based on P(MMA-co-Sty) and PVDF blend for fast-charging lithium metal batteries with extended cycle life

In the quest for high-energy-density lithium metal batteries (LMBs), the stabilization of lithium (Li) metal anodes during fast charging remains a formidable challenge. In this study, a novel copolymer, Poly(methyl methacrylate-co-styrene) (namely PMS) is synthesized and blended with Poly(vinylidene fluoride) to fabricate a porous gel polymer electrolyte (GPE, namely PMS-PVDF) through the nonsolvent-induced phase separation technique, which significantly enhances the electrochemical stability and fast-charging capabilities of LMBs. The developed GPE exhibits a high ionic conductivity of 5.62 mS cm−1, thereby reducing the formation of detrimental Li dendrites and leading to over 400 h stripping/plating process at 0.5 mA cm−2. Extensive electrochemical tests show that the LMBs with the obtained PMS-PVDF GPE achieve exceptional cycle stability over 600 and 1000 cycles at the C-rates of 0.5 and 3 C, respectively, outperforming traditional electrolytes. Furthermore, the ultra-stability of the quasi-solid-state electrolyte is demonstrated in a 375 mAh pouch cell setup, suggesting an essential trait for the practical application of high-power devices. This work marks a pivotal contribution to the field of energy storage, delivering insights and a clear methodology that pave the way for the development of next-generation LMBs poised for commercial viability.

Bacterial Cellulose/Zwitterionic Dual-network Porous Gel Polymer Electrolytes with High Ionic Conductivity

Bacterial Cellulose/Zwitterionic Dual-network Porous Gel Polymer Electrolytes with High Ionic Conductivity

Investigation on the properties of PVDF matrix composite porous gel polymer electrolyte doped with lithium silicon gel

Gel polymer electrolytes are safer because they do not contain liquid phase components. On this basis, the introduction of inorganic fillers effectively overcame the problem of low ionic conductivity of polymer electrolyte at room temperature, and the constructed composite polymer electrolyte (CPEs) combined the advantages of inorganic fillers and polymer segments. In this paper, lithium silicon gel SiO2(Li+) was prepared by in-situ polymerization and sol-gel method, and doped in PVDF composite porous gel polymer electrolyte film prepared by immersion precipitation method. The electrochemical properties and surface topography of lithium iron phosphate were investigated by mounting a bonded lithium iron phosphate quasisolid lithium-ion battery. The experimental results show that the solid electrolyte film modified by SiO2(Li+) has good electrochemical and a certain reference value.

Internally Connected Porous Polymer Electrolyte Membrane for Long-Lasting Flexible Zinc-Air Batteries

The market of various wearable devices is rapidly growing in the recent. Accordingly, a light, safe, and flexible power source is also required to operate. The lithium-ion batteries (LIBs) are optimized for portable devices and can be miniaturized, but they are vulnerable due to the use of organic electrolytes and have limited theoretical energy density. The zinc-air battery (ZAB), as a next-generation battery, have garnered attention for its specific energy density (~1350 Wh/kg) and price competitiveness compared to the LIB. In particular, the use of an aqueous-based polymer electrolyte can provide safety and flexibility, making it a promising energy source for wearable devices. However, the open cathode structure of ZABs for breathing air as an active material leads to gradual loss of liquid components in the polymer electrolyte, resulting in decreased performance.Herein, we developed a porous hybrid polymer membrane to overcome the aforementioned issues by means of the introduction of superabsorbent polymer (SAP) and the formation of internal network design of the membrane. First, a polyacrylic acid (PAA), one of the SAP, based fibrous network was constructed through an electrospinning process. Second, polyvinyl alcohol (PVA) as an ion conductive polymer was cast on the PAA framework, and subsequently impregnated with KOH electrolyte to form a gel-polymer electrolyte (GPE). Interestingly, the sacrificial PAA framework forms internal pores along with the fiber network, which can act as water pockets affording fast ionic conduction through the membranes and providing a higher electrolyte retention effect. As a result, the hybrid GPE had approximately three times higher ionic conductivity compared to pure PVA and better retention, resulting in outstanding electrochemical performance and cycle-life of the ZAB cell. We believe that our unique design approach for GPE can accelerate the commercialization of flexible ZABs and extend the market of wearable devices. Figure 1

A Flexible and Biomimetic Olfactory Synapse with Gasotransmitter‐Mediated Plasticity (Adv. Funct. Mater. 18/2023)

Biomimetic Olfactory Synapses In article number 2214139, Lan Yin and co-workers propose, a flexible and biomimetic olfactory synapse based on organic electrochemical transistors coupled with breath-figure derived porous solid polymer electrolytes. The device demonstrates a ppb-level response limit and desirable selectivity toward hydrogen sulfide, and gas-mediated synaptic plasticity and typical synaptic behaviors are accomplished.

Discovering Reactant Supply Pathways at Electrode/PEM Reaction Interfaces Via a Tailored Interface-Visible Characterization Cell.

In situ and micro-scale visualization of electrochemical reactions and multiphase transports on the interface of porous transport electrode (PTE) materials and solid polymer electrolyte (SPE) has been one of the greatest challenges for electrochemical energy conversion devices, such as proton exchange membrane electrolyzer cells (PEMECs), CO2 reduction electrolyzers, PEM fuel cells, etc. Here, an interface-visible characterization cell (IV-CC) is developed to in situ visualize micro-scaled and rapid electrochemical reactions and transports in PTE/SPE interfaces. Taking the PEMEC of a green hydrogen generator as a study case, the unanticipated local gas blockage, micro water droplets, and their evolution processes are successfully visualized on PTE/PEM interfaces in a practical PEMEC device, indicating the existence of unconventional reactant supply pathways in PEMs. Further comprehensive results reveal that PEM water supplies to reaction interfaces are significantly impacted with current densities. These results provide critical insights about the reaction interface optimization and mass transport enhancement in various electrochemical energy conversion devices.

Fabrication of a porous polymer electrolyte from poly(vinylidene fluoride-hexafluoropropylene) via one-step reactive vapor-induced phase separation for lithium-ion battery

Fabrication of a porous polymer electrolyte from poly(vinylidene fluoride-hexafluoropropylene) via one-step reactive vapor-induced phase separation for lithium-ion battery

A Flexible and Biomimetic Olfactory Synapse with Gasotransmitter‐Mediated Plasticity

AbstractNeuromorphic electronics has demonstrated great promise in mimicking the sensory and memory functions of biological systems. However, synaptic devices with desirable sensitivity, selectivity, and operational voltage imitating the olfactory system have rarely been reported. Here, a flexible and biomimetic olfactory synapse based on an organic electrochemical transistor (OECT) coupled with a breath‐figure derived porous solid polymer electrolyte (SPE) is proposed. The device demonstrates excellent sensitivity with a ppb‐level response limit and desirable selectivity toward hydrogen sulfide (H2S) over other gases, and successfully achieves wireless real‐time detection of excessive concentration of H2S from rotten eggs. H2S‐mediated synaptic plasticity is accomplished with the device and typical synaptic behaviors are realized, including short‐term memory (STM), long‐term memory (LTM), transition from STM to LTM, etc., enabling the imitation of potential cumulative damages upon H2S exposure. The proposed device paves new ways toward next‐generation olfactory systems capable of sensing and memorizing functionalities mimicking neurobiological systems, offering critical materials strategies to accomplish intelligent artificial sensory systems.

Construction of shrimp shell (SS) waste-based carbon electrode-gel polymer electrolyte (GPE) system for flexible symmetric supercapacitors

Shrimp shell waste based hierarchical porous carbon and gel polymer electrolytes (GPE) were prepared for supercapacitors.

Biodegradable poly-ε-caprolactone based porous polymer electrolytes for high performance supercapacitors with carbon electrodes

Herein, we report porous polymers electrolytes (PPEs), composed of a biodegradable polymer poly-ε-caprolactone (PCL), activated with organic liquid electrolyte (ethylene carbonate (EC)/propylene carbonate (PC)/NaClO4) and an ionic liquid (IL)-incorporated electrolyte (1-ethyl-3-methylimidazolium trifluoromethane-sulfonate (EMITf)/Na-trifluoromethane sulfonate (NaTf). The porous polymeric membranes are prepared via a simple, one step immersion precipitation method, which provide channels for ionic transport. Morphological/structural, thermal and electrochemical studies on PPEs exhibit excellent flexibility, good porosity (∼80%), high (∼90%) liquid electrolyte uptake and high room temperature ionic conductivity (1.8–1.9 × 10−3 Scm−1) with wide electrochemical stability window (>5.0 V). Quasi-solid-state carbon supercapacitors/electrical double layer capacitors (EDLCs) are fabricated from symmetrical activated carbon (AC) electrodes (derived from a waste-biomass, sugarcane bagasse), separated by PPE-films. The supercapacitor based on IL-incorporated PPE exhibits higher specific capacitance (∼170 F g−1) and specific energy (∼34 Wh kg−1) compared to the device based on organic solvents-based PPEs (∼130 F g−1 and ∼24 Wh kg−1, respectively). Substantial energy storage in supercapacitor is evident from the glow of LED (35–50 mW) for longer duration. The device demonstrates stable performance up to ∼10,000 charge-discharge cycles with ∼15% initial capacitance fading and ∼100% Coulombic efficiency.

Effect of Zr-Nanofiller on Structural and Thermal Properties of PVDF-co-HFP Porous Polymer Electrolyte Membranes Doped with Mg2+ Ions

New poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-co-HFP)/ZrO2-based nanocomposite porous polymer membranes were prepared with doping of magnesium ions using THF as solvent. These membranes were prepared using the solvent casting technique. The optimal nanofiller (0, 2, 4, 6, 8 and 10% Zr nanopowder) was incorporated into the PVDF-co-HFP/MgTf3/ZrO2 and the incorporation of the nanofiller results in an increase in the porosity of the prepared membranes. The structural, morphological and thermal properties of the nanocomposite porous polymer membranes were also investigated. The structural investigation and the identification of functional groups were accomplished using FTIR technique. X-ray diffraction (XRD) analysis was performed to ascertain the phase of polymer membranes and the phase change that happens upon interaction with nanofiller and Mg2+ ions. Assessment of the nanocomposite porous polymer membrane's morphology and porous structure was performed using a scanning electron microscope (SEM). DSC analysis was used to evaluate the thermal behaviour of the nanocomposite porous membranes. The electrical and dielectric studies confirmed the structural reformation of the polymer electrolyte materials. It was found that 8% nanofiller is the best conducting composition for maximum ionic conductivity, dielectric constant and Mg2+ ion mobility. The incorporation of ZrO2 nanofiller predominantly increases the number of free ions and mobility of the charge carriers in the composite polymer electrolyte systems.

Lithium-Rich Porous Aromatic Framework-Based Quasi-Solid Polymer Electrolyte for High-Performance Lithium Ion Batteries.

The development of solid polymer electrolytes (SPEs) with high ionic conductivity, wide electrochemical window, and high mechanical strength is the key factor to realize high-energy-density solid lithium ion batteries (SLIBs). Porous aromatic frameworks (PAFs) have the advantages of high porosity, easily functionalized molecular structure, and rigid stable framework, which fully meet the requirements of solid polymer electrolytes with high Li+ capacity, fast Li+ transport, and safety. Herein, a lithium-rich amidoxime (AO)-modified porous aromatic framework (PAF-170-AO) was obtained through the absorption of LiTFSI by amidoxime groups and abundant pores and then compounded with poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) to prepare a PAF-based quasi-solid polymer electrolyte (PAF-QSPE) with only tiny amounts of plasticizer (∼12 μL). The amidoxime groups of PAF-170-AO restricted the movement of the anions of LiTFSI through hydrogen bonding, which effectively promoted the dissociation and migration number of Li+ (tLi+), reduced the concentration polarization, and inhibited the growth of lithium dendrites. The PAF-QSPE exhibited a high ionic conductivity of 1.75 × 10-4 S cm-1 and tLi+ of 0.55 at room temperature. The activation energy was as low as 0.136 eV. Furthermore, the assembled SLIBs with the PAF-QSPE presented a discharge capacity of 163 mAh g-1 at 0.2 C and a capacity retention rate of 96% after 350 cycles, illustrating a stable cycling performance. This work demonstrated the great application potential of lithium-rich PAFs in QSPEs.

(Digital Presentation) H-BN Enhanced Gel Polymer Electrolyte for Solid State Li-Ion Batteries

In order to address safety concerns of conventional carbonate liquid electrolytes, porous gel polymer electrolytes (GPE) can effectively encapsulate the solution while providing good electrolyte-electrode contact. In this work, a GPE is incorporated with exfoliated 2D hexagonal boron nitride nanosheets (BNNS) as an effective and safe polymer electrolyte for Li-ion batteries. With a facile Dr. Blade approach combined with phase inversion, a high porosity and electrolyte uptake can be maintained while still acting as a stable film. Utilising a 15 wt.% binary polymer mixture of polyvinylidene fluoride (PVDF) and polyethylene oxide (PEO) doped with exfoliated BN flakes, the final GPE is not only more thermal stable but able to effectively suppress dendrite growth through multiple cycles with a high ionic conductivity of 3.03 x10-3 S/cm at ambient conditions. Cell performance with this GPE includes strong cycling performance while sustaining a high coulombic efficiency. Figure 1

Mechanically robust epoxy resin-based gel polymer electrolyte stabilizing ion deposition for high-performance lithium metal batteries

Lithium metal batteries (LMBs) with extremely excellent energy density exhibit highly potential for future power applications. However, due to the dendrite growth caused by the strong activity of lithium metal, severe safety concerns and low life range are still great challenges for LMBs. Herein, a porous epoxy resin-based gel polymer electrolyte (PEE) with a special structure of the skeletal network fully filled with epoxy resin globules is developed. The PEE membranes with abundant communicating pores channels and rich polar groups (–OH, C–O–C) show high lithium ion conductivity and robust mechanical performance (the Young's modulus of 312 MPa after activation by liquid electrolyte) as well as superior thermal stability (no dimensional change at 250 °C). Furthermore, the typical PEE-2.75 membrane can restrain lithium dendrites growth effectively and stabilize lithium ion deposition (over 1000 h of stable operation at 2 mA cm−2). Therefore, the full cell Li//PEE-2.75//LiFePO4 shows a significant rate capacity of 92.8 mA h g−1 at 5 C and stable cycle performance (capacity maintained at over 82.33% after 195 cycles at 1 C). This work presents a simple and effective way for the application of epoxy resin in high-performance LMB.

Hierarchically Porous Gel Polymer Electrolyte with Improved Ionic Conductivity Enabled by Interpenetrating Polymer Network for Flexible Zn-Air Batteries

Hierarchically Porous Gel Polymer Electrolyte with Improved Ionic Conductivity Enabled by Interpenetrating Polymer Network for Flexible Zn-Air Batteries

Fabrication of a Porous Polymer Electrolyte from Poly(Vinylidene Fluoride-Hexafluoropropylene) Via a One-Step Reactive Vapor Induced Phase Separation for Lithium Ion Battery

Fabrication of a Porous Polymer Electrolyte from Poly(Vinylidene Fluoride-Hexafluoropropylene) Via a One-Step Reactive Vapor Induced Phase Separation for Lithium Ion Battery

PVDF-HFP based polymer electrolytes with high Li+ transference number enhancing the cycling performance and rate capability of lithium metal batteries

Lithium metal batteries are confronted with safety issues in liquid electrolyte systems owing to rapid growth of lithium dendrite and uneven lithium deposition. Exploration of gel polymer electrolytes (GPEs) with excellent ionic conductivity and high Li+ migration number is a possible strategy to replace liquid electrolyte. Herein, a high-powered GPEs relied on poly (vinylidene fluoride-hexafluoro propylene) (PVDF-HFP) modified by polymer polyethylene glycol (PEG) and lithium montmorillonite (LiMNT) via bond interactions is reported. The prepared porous polymer electrolyte presents a captivating ionic conductivity of 1.82 × 10−3 S·cm−1 and lithium ions transference number up to 0.513 at 25 °C. In view of the eminent ionic conductivity and efficient migration number of Li+, the three-dimensional porous polymer electrolyte is very conducive to the fast transport and stable deposition of lithium ions, restraining the occurrence and growth rate of lithium dendrites, which improves the cycle performance and rate capability of lithium battery. LiFePO4| PPL122 electrolyte |Li battery delivers a desired cycling performance with a capacity retention of 92% after 1000 cycles at 1 C.

A Three-Dimensional Electrospun Li6.4La3Zr1.4Ta0.6O12-Poly (Vinylidene Fluoride-Hexafluoropropylene) Gel Polymer Electrolyte for Rechargeable Solid-State Lithium Ion Batteries.

Developing high-quality solid-state electrolytes is important for producing next-generation safe and stable solid-state lithium-ion batteries. Herein, a three-dimensional highly porous polymer electrolyte based on poly (vinylidenefluoride-hexafluoropropylene) (PVDF-HFP) with Li6.4La3Zr1.4Ta0.6O12 (LLZTO) nanoparticle fillers (PVDF-HFP-LLZTO) is prepared using the electrospinning technique. The PVDF-HFP-LLZTO gel polymer electrolyte possesses a high ionic conductivity of 9.44 × 10–4 S cm−1 and a Li-ion transference number of 0.66, which can be ascribed that the 3D hierarchical nanostructure with abundant porosity promotes the liquid electrolyte uptake and wetting, and LLZTO nanoparticles fillers decrease the crystallinity of PVDF-HFP. Thus, the solid-state lithium battery with LiFePO4 cathode, PVDF-HFP-LLZTO electrolyte, and Li metal anode exhibits enhanced electrochemical performance with improved cycling stability.

Solid-state batteries designed with high ion conductive composite polymer electrolyte and silicon anode

Polymer solid-state batteries (SSBs) possess the advantages of good interfacial contact, but their application faces low ionic conductivity. Here, three-dimensional (3D) porous composite polymer electrolytes with propylene carbonate plasticizer (3D-PPLLP-CPEs) fabricated effectively, displaying high ionic conductivity even at room temperature. Electrochemical in-situ polymerization of 3D-PPLLP-CPEs occurs during the first discharge process, avoiding safety issues caused by the liquid plasticizer without sacrificing the ionic conductivity of the electrolyte. Besides, the controllable in-situ generated LiF-enriched interface can avoid the Li dendrite growth. To further promote the practical value of SSBs, micro-sized Si@Li3PO4@C with high initial Coulombic efficiency was adopted to replace lithium foil. The LiNi1/3Co1/3Mn1/3O2 (NCM111)//Micro Si@Li3PO4@C full cell has achieved capacity of 129.1 mAh g−1 at a current density of 0.2 C, with capacity retention of 98.5% after 100 cycles, which is the best performance based on the Si anode in SSBs. Even at the high current density of 2.0 A g−1, the capacity remains 92.5 mAh g−1. This design of CPEs and electrodes has paved a new way to construct practical SSBs.

Fabrication of Borate-Based Porous Polymer Electrolytes Containing Cyclic Carbonate for High-Performance Lithium Metal Batteries

A series of borate-based porous polymer electrolytes (B-PPEs) is prepared by incorporating the copolymers containing cyclic boroxine and cyclic carbonate groups into poly(vinylidene fluoride) (PVDF) through the phase inversion method. The dense and well-interconnected pores are obtained in the polymer matrix when the content of the copolymer reached 40 wt %. The ethylene–oxygen chain segments in the copolymer can facilitate the mobility of polymer chains and form the uniform distribution of pores in the B-PPEs. The B-PPEs show an enhanced ionic conductivity of 1.32 × 10–3 S cm–1 at 30 °C, which is due to the uniform well-interconnected pores in the polymer host. The cyclic carbonate units interact with the liquid electrolyte, which could improve the electrolyte uptake capacity of the polymer matrix. Benefited from the Lewis acid–base interactions between boron moieties and the anions of the lithium salt, the lithium-ion transference number of B-PPEs is also significantly improved. Compared to the pure PVDF-based electrolyte, the Li/B-PPEs/Li cell displays a very stable polarization voltage and the long-time cycling for 1000 h at a current density of 0.2 mA cm–2. Moreover, the Li/B-PPEs/LiFePO4 cells deliver a higher capacity of 143.0 mAh g–1 at 0.2 C and 86% capacity retention after 150 cycles. The B-PPEs could be a promising candidate for enhancing the safety and electrochemical properties of lithium metal batteries.