Ionic Liquid Gel Polymer Electrolyte Research Articles

Development of dialkyl-triazolium ionogels for printed supercapacitor

The use of electrolytes has a very crucial role in supercapacitors. Liquid electrolytes cause many problems, like leakage, whereas aqueous electrolytes show only lower potential windows. These are improved by ionic liquid gel polymer electrolytes. In this work, we have synthesized 4 ILs, namely 1,4-dipropyl-1,2,4-triazolium BF4,1-propyl-4-butyl-1,2,4-triazolium BF4, 1,4-dipropyl-1,2,4-triazolium PF6,and 1-propyl-4-butyl-1,2,4-triazolium PF6 and studied their thermal and electrochemical properties. From them, the most efficient 1,4-dipropyl-1,2,4-triazolium BF4 IL is combined with PVA polymer, made into gel polymer electrolyte, coated over a carbon screen-printed electrode, and tested. The fabricated solid-state capacitor prototype yields a capacitance of 98.8 mFcm−2 at a least scan rate of 2 mV/s and the calculated areal energy density and areal power density were 0.221 µWh and 52 µWcm−2 respectively. Cyclic stability with GCD gave 80 % capacitive retention even after 3000 cycles.

Development of dicationic 1,2,4-triazolium salts and their application as solid-state electrolyte for energy storage

Here, in this study we report the synthesis and characterizations of novel electrolyte based on dicationic salts 1,3-bis(1-alkyl-1,2,4-triazolium)mesitylene bis(tetrafluoroborate). Two cations were linked by mesitylene as spacer. Using 1H NMR, 13C NMR, FTIR and RAMAN spectroscopy methods the structural characterization of synthesized salts were done. Cyclic voltammetry, electrochemical impedance spectroscopy, thermogravimetry analysis, and differential scanning calorimetry have all been used to examine their thermal, electrochemical, and transport properties. Their suitability for energy storage was examined by fabricating a cell out of it in a Swagelok, where ionic liquid gel polymer electrolyte (ILGPE) was used as electrolyte and the graphite-PTFE sheet functioned as an electrode to construct a symmetrical EDLC. A wide working electrochemical potential window range of 0 to 4.5 V was obtained after studying the electrochemical cell performance, indicating that the dicationic salts can be employed as a promising electrolyte. It provided an effective areal capacitance of 63.13 F/cm2. Even after 2000 consecutive cycles of charging and discharging, the fabricated device continues to retain about 80 % of its initial capacitance. The GCD curves provided computed values for energy and power density of 1.1 μWh and 317.5 μW/cm2, respectively.

Boosting the Sensitivity and Hysteresis of a Gel Polymer Electrolyte by Embedding SiO2 Nanoparticles and PVP for Humidity Applications.

Enhancing sensitivity and hysteresis in capacitance humidity sensors is vital for precise, reliable, and consistent humidity control. This study explores this concern by incorporating polyvinylpyrrolidone (PVP) and SiO2 nanoparticles into a polyvinyl alcohol (PVA)-based ionic liquid gel polymer electrolyte (ILGPE), studying two capacitor types: ILGPE and SiO2 composite ILGPE (CILGPE) capacitors. These novel electrolytes use ammonium acetate as a plasticiser, 1-butyl-3-methylimidazolium bromide as an ionic liquid, SiO2 nanoparticles as a composite, and PVA and PVP as host polymers. Capacitors were characterised and modelled using impedance spectroscopy (IS), providing an electrophysical insight into their working principle. Sensitivity and hysteresis were evaluated within a 20-90% relative humidity (RH) range at 25 °C. The SiO2 CILGPE capacitor with PVP presented superior sensitivity and hysteresis, revealing the beneficial combination of SiO2 nanoparticles and PVP. These benefits are due to the creation of pathways that facilitate water molecule diffusion and crystallinity reduction in PVA-ILGPE. In particular, at 10 kHz, it demonstrates a calibrated capacitance sensitivity of 2660 pF/%RH and a hysteresis of 3.28 %RH. This optimised capacitor outperforms some previous humidity capacitive sensors in sensitivity while exhibiting low hysteresis.

Flexible High-Energy-Density 4.3 V Supercapacitor Based on a Trimetallic Sulfide Cathode and a Bimetallic Sulfide-Polypyrrole Anode with an Ionic Liquid Gel Polymer Electrolyte

Flexible High-Energy-Density 4.3 V Supercapacitor Based on a Trimetallic Sulfide Cathode and a Bimetallic Sulfide-Polypyrrole Anode with an Ionic Liquid Gel Polymer Electrolyte

Biorenewable Calcite as an Inorganic Filler in Ionic Liquid Gel Polymer Electrolytes for Supercapacitors.

Supercapacitors play a crucial role in the global shift toward cleaner, renewable energy and away from fossil fuels. Ionic liquid electrolytes have a larger electrochemical window than some organic electrolytes and have been mixed with various polymers to make ionic liquid gel polymer electrolytes (ILGPEs), a solid-state electrolyte and separator combination. One way to improve the conductivity of these electrolytes is to add inorganic materials such as ceramics and zeolites to increase their ionic conductivity. Herein, we incorporate a biorenewable calcite from waste blue mussel shells as an inorganic filler in ILGPEs. ILGPEs composed of 80 wt % [EMIM][NTf2] and 20 wt % PVdF-co-HFP are prepared with various amounts of calcite to determine the effect on the ionic conductivity. The optimal addition of calcite is 2 wt % based on the mechanical stability of the ILGPE. The ILGPE with calcite has the same thermostability (350 °C) and electrochemical window (3.5 V) as the control ILGPE. Symmetric coin cell capacitors were fabricated using ILGPEs with 2 wt % calcite and without calcite as a control. Their performance was compared using cyclic voltammetry and galvanostatic cycling. The specific capacitances of the two devices are similar, 110 and 129 F g-1, with and without calcite, respectively.

Phosphonate-Functionalized Ionic Liquid Gel Polymer Electrolyte with High Safety for Dendrite-Free Lithium Metal Batteries.

The conventional lithium-ion battery technology relies on the liquid carbonate-based electrolyte solution, which causes excessive side reactions, serious risk of electrolyte leakage, high flammability, and significant safety hazards. In this work, phosphonate-functionalized imidazolium ionic liquid (PFIL) is synthesized and used as a gel polymer electrolyte (GPE) to replace the organic carbonate-based electrolyte solution. The as-prepared ionic liquid-based gel polymer electrolyte (IL-GPE) shows low crystallinity, flame retardance, and excellent electrochemical performance. Thanks to the fast double channel transport of lithium ions in the IL-GPE electrolyte, a high ionic conductivity of 0.48 mS cm-1 and a lithium-ion transference number of 0.37 are exhibited. Symmetrical lithium cells with IL-GPE retain stable cycling even after 3000 h under 0.1 mA cm-2. IL-GPE exhibits good compatibility toward lithium metal, yielding excellent long-term electrochemical kinetic stability. IL-GPE induces the formation of a uniform and robust SEI layer, inhibiting the growth of lithium dendrites and improving the rate performance and cycle stability. Furthermore, Li/LiFePO4 cells exhibit a specific capacity of 63 mA h g-1 after 150 cycles at 5.0 C, with a capacity retention of 90.2%. It is foreseen that this GPE is a promising candidate to enhance the safety of high-performance lithium metal batteries.

Preparation of imidazolium based polymerized ionic liquids gel polymer electrolytes for high-performance lithium batteries

Ionic liquid gel polymer electrolytes (GPE) possess advantages of high ionic conductivity, outstanding safety and high compatibility with electrodes. However, the ionic liquid plasticizers in GPE for elevating the ionic conductivity will decrease the mechanical strength of GPE. Polymerized ionic liquids (PIL) combine the properties of polymer and ionic liquids, so the application of them possesses several superiorities beyond ionic liquids. In this research, one PIL poly(1-[2-(2-(2-(Methacryloyloxy)ethoxy)ethoxy)ethyl]-3-methylimidazolium bis(trifluoromethylsulfonyl)imide)-co-poly(poly(ethylene glycol) methyl ether methacrylate) is synthesized and blended with host polymer PVDF, ionic liquid (1-butyl-1-methylimidazolium bis(trifluoromethylsulfonyl)imide, [BMIM]TFSI) and lithium salt LiTFSI to prepare PIL gel electrolyte (PIL-GPE@IL) membrane applying in lithium battery. Besides the moderate mechanical strength, the PIL-GPE@IL combined with ionic liquid display a high ion conductivity of 1.76 × 10−3 S cm−1 at 30 °C and outstanding electrochemical stability with an oxidation potential of 4.26 V vs. Li+/Li. Furthermore, the Li/LiFePO4 cells assembled with the PIL-GPE@IL show excellent rate performance and cycle performance, which exhibit an initial specific discharge capacity of approximate 143 mAh g−1 at current density of 0.5C accompanied by an excellent capacity retention of 97% within 120 cycles. This work demonstrates the capability of the as-prepared PIL-GPE@IL using in lithium batteries to boost the performance.

Ionic liquid gel polymer electrolytes for flexible supercapacitors: Challenges and prospects

Ionic liquid gel polymer electrolytes (IL-GPEs) have attracted wide interest in the field of electrochemical energy storage devices, particularly for their use in flexible supercapacitors (FSCs). IL-GPEs integrate ionic liquids (ILs) as either a solvent or as a polymerizable unit. They possess several attractive properties including high ionic conductivity, wide operating potential range, good thermal stability, tunable chemical functionalities and self-healing capabilities. In this short review, an overview of IL-GPEs is provided, first describing their classification, fundamental properties, and chemical design, then detailing some of the most recent essential advances in the field along with their limitations. • Flexible supercapacitors are desirable due to light weight, flexibility, and comfort when wearing. • Ionic liquid gel polymer electrolytes (IL-GPEs) open up new possibilities for multi-functional FSCs. • This mini-review paper describes recent advancements of IL-GPEs used in FSCs over the past three years. • Selecting a specific IL for a given gel scaffold material is crucial when exploring new FSC materials.

Double-layer Composite Gel Polymer Electrolyte for Organic Sodium-Metal Batteries.

Organic cathode materials have the advantages of abundant raw materials, high theoretical specific capacity, controllable structure and easy recycling. Pyrene-4,5,9,10-tetraone (PTO), as one of the typical organic cathode materials, achieves efficient storage and release of Na+ . However, its good solubility in traditional organic liquid electrolytes is detrimental to the cyclic stability of batteries. To address this issue, the double-layer composite gel polymer electrolyte (DLCGPE) consisting of poly (ionic liquid) gel polymer electrolyte and plastic crystal electrolyte was developed and applied to organic sodium-metal batteries. This as-prepared DLCGPE displays an ionic conductivity of 2.17×10-4 S cm-1 and an electrochemical window of 4.8 V. The as-fabricated sodium-symmetric batteries maintain interfacial stability after 500 h of cycling. Furthermore, the PTO/Na batteries could also retain a specific capacity of 201 mAh g-1 after 300 cycles, confirming that DLCGPE achieves the purpose of inhibiting PTO dissolution and maintaining batteries stability. This work broadens the application of asymmetric electrolytes in organic secondary battery.

Flexible Aluminum-Air Battery Based on Ionic Liquid-Gel Polymer Electrolyte.

There is an urgent demand to develop high-performance flexible batteries for a wide range of contemporary emerging fields, including flexible electronics, wearable sensors, and implantable medical devices. However, the inherent safety and stability issues of traditional organic liquid-based electrolytes make their application in flexible batteries unsatisfactory. Therefore, exploring gel electrolytes with superior ionic conductivity and safety is considered to be the key to the development of flexible batteries. In this paper, two types of high-quality ionic liquid-based gel polymer electrolyte membranes (PVDF-ILs) are created by a conventional solution-casting method, which are further integrated into flexible aluminum-air batteries to guide the interface and process research, and the related discharge properties of two ionic liquid-based electrolyte membrane (PVDF-[C4mpyr]Cl, PVDF-[BMIM]Cl) in different bending states are discussed. The results show that PVDF-ILs have a rich pore structure and interwoven skeleton network, leading to relatively high ionic conductivity (2.97 × 10-3 S cm-1). Moreover, two types of batteries can meet the needs of flexibility, although there is a slight loss of power density under various bending conditions. In general, a PVDF-[C4mpyr]Cl-based flexible aluminum-air battery is suitable for the working conditions of high power and low bending angle, while the PVDF-[BMIM]Cl-based flexible aluminum-air battery is favored for microwatt low-power devices with high flexibility requirements.

Space-charge limited ionic conductivity enhancement in gel polymer electrolyte capacitors by embedding nanoparticles

In this work, a novel mixture of ionic liquid gel polymer electrolyte (ILGPE), containing 1-butyl-3-methylimidazolium bromide, ammonium acetate and poly(vinyl alcohol), with Si@C and SiO2 embedded nanoparticles is fabricated. The resulting CILGPE is deposited onto interdigitated electrodes. The fabricated electrolytes have been characterised by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) and the resulting capacitors have been characterised by impedance spectroscopy (IS) and linear sweep voltammetry (LSV) and modelled. The specific capacitance for capacitor with ILGPE is 0.042Fcm−3, while for the capacitor with SiO2 and Si@C embedded in ILGPE are 0.072 Fcm−3 and 0.06 Fcm−3, respectively. Therefore, the addition of SiO2 and Si@C nanoparticles improves the capacitance by 71% and 42%, respectively. The results of fitting I-V curves exhibit reductions in both the activation voltage (Vtr) and in the voltage that indicates the traps are filled (VTFL) with the addition of nanoparticles, revealing an increase in charge contribution. We propose that the capacitance enhancement is due to the contribution of nanoparticles to: (i) the creation new effective ion transport pathways, (ii) ion dissociation in the electrolyte and (iii) the crystallinity reduction of ILGPE. This work contributes with new findings about the effect of nanoparticles on the Space-charge-limited-conduction (SCLC) mechanism and how these changes in transport mechanism are related to the series and leakage resistances, capacitance, and physicochemical properties.

The Influences of 1-Butyl-3-Methylimidazolium Tetrafluoroborate on Electrochemical, Thermal and Structural Studies as Ionic Liquid Gel Polymer Electrolyte

After decades of development, ionic liquid gel polymer electrolytes (ILGPEs) are currently experiencing a renaissance as a promising electrolyte to be used in electrochemical devices. Their inherent tendency towards poor electrochemical properties have limited their applications and commercialization activities. Henceforth, gel polymer electrolyte (GPE) is being introduced to alleviate the abovementioned issues. In this work, the assessment of the ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate [BMIM][BF4] in poly (vinylidene fluoride-hexafluoropropylene) (PVDF-HFP) to form ILGPE was done. The relationship of [BMIM][BF4] towards the dielectric properties at different wt. % ratios and temperature was ascertained. The results indicated that [BMIM]BF4 is able to facilitate fast conduction. Moreover, it was found that [BMIM][BF4] could serve as an effective agent in reducing crystallinity and glass transition temperature of the polymer and thus enhanced the ionic conductivity of the samples. Notwithstanding, the ILGPE sample possessed a high thermal stability up to 300 °C and good electrochemical stability of 4.2 V which are beneficial for operation in electrochemical devices. All in all, the correlation between the ionic liquid chemistry and electrochemical performances could provide a valuable insight to rational selection and design for ILGPE electrolytes.

Effect of interface wetting on the performance of gel polymer electrolytes-based solid-state lithium metal batteries

Solid-state lithium metal batteries are the one of most promising energy storage devices. To date, however, it is still considered that the interface wetted by liquid electrolytes can enhance the performance of solid-state lithium batteries. In this work, the resistance of the batteries versus their cycle number is investigated using 1 M LiPF6 EC/DMC (v/v = 1/1) (LE) and 1 M LiTFSI-PP13TFSI (IL) wetting the interface of the LiFePO4 cathode and the ionic liquid gel polymer electrolyte (ILGPE). The results indicate that, compared with IL-wetting, LE-wetting treatment can more effectively lower the bulk resistance of the battery. The bulk resistance of the batteries does not alter after cycling, indicating that the ionic conductivity is stable during the charging/discharging. The interfacial resistance and charge transfer resistance of LE-wetted batteries increase by 50 times and 825 times after 50 cycles at C/3 and 23 °C, while the resistance of IL-wetted batteries increase by less than 20 times. Furthermore, the formation of the electrode electrolytes interphase during cycling, which probably accounts for the change of battery resistance observed in solid-state lithium batteries. The ILGPE had superior compatibility and stability with LiFePO4 cathode, which is also the most basic guarantee for the battery's stable cycling.

Poly(3,4-ethylenedioxythiophene) Based Solid-State Polymer Supercapacitor with Ionic Liquid Gel Polymer Electrolyte.

In this work, solid-state polymer supercapacitor (SSC) was assembled using poly(3,4-ethylenedioxythiophene/carbon paper (PEDOT/CP) as an electrode and ionic liquid (1-butyl-3-methylimidazole tetrafluoroborate)/polyvinyl alcohol/sulfuric acid (IL/PVA/H2SO4) as a gel polymer electrolyte (GPE). The GPE was treated through freezing–thawing (F/T) cycles to improve the electrochemical properties of PEDOT SSC. Cyclic voltammetry (CV), galvanostatic charge–discharge measurements (GCD) and electrochemical impedance spectroscopy (EIS) techniques and conductivity were carried out to study the electrochemical performance. The results showed that the SSC based on ionic liquid GPE (SSC-IL/PVA/H2SO4) has a higher specific capacitance (with the value of 86.81 F/g at 1 mA/cm2) than the SSC-PVA/H2SO4.The number of F/T cycles has a great effect on the electrochemical performance of the device. The energy density of the SSC treated with 3 F/T cycles was significantly improved, reaching 176.90 Wh/kg. Compared with the traditional electrolytes, IL GPE has the advantages of high ionic conductivity, less volatility, non-flammability and wider potential window. Moreover, the IL GPE has excellent elastic recovery and self-healing performance, leading to its great potential applications in flexible or smart energy storage equipment.

Performance of a rechargeable cell using an ionic liquid gel polymer electrolyte and natural graphite electrode

With the concepts of green environment and the priority given on economical aspects, a great deal of research activities has been diverted towards clean and low-cost device fabrication. Central focus was on eliminating the use of toxic and expensive materials like Li and different solvents. Application of ionic liquid-based gel polymer electrolytes (GPEs) and non-Li electrodes can address many shortcomings associated with liquid, solid and GPEs. In the present study, characteristics of a rechargeable cell with 1-ethyl-3-methylimidazolium trifluoromethanesulphonate-based GPE having Zn and Sri Lankan natural graphite electrodes have been investigated. For characterization, electrochemical impedance spectroscopy, cyclic voltammetry and galvanostatic charge discharge test have been performed at room temperature. The open circuit voltage of the cell was about 1V. Specific charge and discharge capacities of the cell were 4.66 and $$2.99 \hbox { mA h g}^{-1}$$, respectively. Moreover, efficiency of the specific charge was 80.2% over 500 cycles, while efficiency of specific discharge was 92% over 1000 cycles. These results proved the suitability of the electrolyte and electrodes investigated in the present study to be used well in rechargeable cells.

High-Performance Ionic Liquid Gel Polymer Electrolytes for Solid-State Lithium Metal Batteries

Lithium metal is considered as a “Holy Grail” anode material for secondary batteries because of its extremely high theoretical specific capacity (3860 mA h g−1), low electrochemical potential (-3.04 V vs. SHE), and low density (0.59 g cm-3). Ionically conductive polymer electrolytes represent a class of environmental-friendly and inflammable electrolytes for solid-state batteries that can enable the use of lithium metal. In our study, we fabricated lithium metal batteries based on transparent self-standing ionic liquid gel polymer electrolytes (ILGPEs) and LiFePO4cathodes. We evaluated the properties of ILGPEs by engineering the compositional space between the constituting components: poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), N-methyl-N-propylpiperidinium bis(trifluoromethanesulfonyl)imide (PP13TFSI), and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI). The ionic conductivity of ILGPE increases with the increase of PP13TFSI and LiTFSI, and a maxima conductivity was obtained when the mass ratio of PP13TFSI, PVDF-HFP, and LiTFSI was 3:1:1, and the value was 1.3 mS cm-1at 22 ºC, and then increased to 5.82 mS cm-1at 80 °C. The optimized ILGPE showed excellent compatibility with lithium metal, determined by the interfacial resistance stability with the elapsed time. The solid-state LiFePO4cells delivered a practical capacity approaching 89.5% of the theoretical capacity and a capacity retention of 95.1% after 200 cycles with a current density of C/5 at 22 ºC. The solid-state lithium metal batteries using various cathodes materials, such as NMC, Co-free layered oxides, disordered rocksalt were also evaluated.

High-performance N-methyl-N-propylpiperidinium bis(trifluoromethanesulfonyl)imide/poly(vinylidene fluoride-hexafluoropropylene) gel polymer electrolytes for lithium metal batteries

Ionically conductive polymer electrolytes represent a class of safe and environment-friendly electrolytes for next-generation alkali metal batteries. Understanding the interplay between composition-driven interfacial processes and battery performance can fundamentally inform the design of polymer electrolytes for practical applications. In this study, we fabricate lithium metal batteries based on transparent free-standing ionic liquid gel polymer electrolytes (ILGPEs) and LiFePO4 cathodes. We develop the ILGPEs using a composite of poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), N-methyl-N-propylpiperidinium bis(trifluoromethanesulfonyl)imide (PP13TFSI), and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI). A thorough compositional optimization shows that the lithium ion conductivity of the ILGPE increases with the increase of PP13TFSI and LiTFSI, reaching maxima of 1.3 mS cm−1 at 23 °C and 5.82 mS cm−1 at 80 °C when the ILGPE contains 60 wt% PP13TFSI and 20 wt% LiTFSI. The optimized ILGPE exhibits excellent interfacial stability against the lithium metal, as signified by the stable interfacial resistance upon long-term storage. The LiFePO4|ILGPE|Li cells can deliver superior battery performance with a practical capacity approaching 89.5% of the theoretical capacity and capacity retention of 95.0% after 200 cycles. The formation of the electrode–electrolyte interphases takes place primarily during the initial cycles, which likely accounts for the activation period observed in LiFePO4|ILGPE|Li cells.

Solid-state supercapacitors based on poly (3, 4-ethylendioxythiophene) (PEDOT) – Manganese oxide (MnO2) composite electrodes synthesized by single-step Co-Deposition for electrical energy storage

In this work, solid-state supercapacitors were fabricated and characterized based on PEDOT-MnO2 electrodes and ionic liquid gel polymer electrolyte. The PEDOT-MnO2 electrodes were synthesized by single-step co-deposition technique in an aqueous solution consisting of 0.1 M LiClO4, 0.01 M EDOT monomer, 0.07 M SDS, and 0.3 M MnSO4. For comparative studies, another electrode was prepared from pure MnO2 that was electrochemically synthesized in exact same way with the exception that the EDOT monomer was not dissolved in the electrochemical deposition aqueous medium. The presence of both PEDOT and MnO2 in the electrochemically prepared electrodes was confirmed by Raman spectroscopy. The electrochemical performance characteristics were evaluated using cyclic voltammetry, charge-discharge tests, and electrochemical impedance spectroscopy. The PEDOT-MnO2 solid-state supercapacitor displayed an optimum areal capacitance density of 73.81 mF cm−2 at 10 mV s−1. The maximum energy and power densities were found to be 15.07 Wh kg−1 and 6.84 kW kg−1, respectively. In addition, the electrochemical performance of both PEDOT-MnO2 and pure MnO2 based solid-state supercapacitors was compared in terms of CV and CD and it was confirmed that the PEDOT-MnO2 electrode had superior electrochemical performance compared to the pure MnO2 electrode. Overall, the PEDOT-MnO2 based solid-state supercapacitor holds great potential for thin, flexible, and lightweight energy storage.

Thermo and electrochemical-stable composite gel polymer electrolytes derived from core-shell silica nanoparticles and ionic liquid for rechargeable lithium metal batteries

With the aim to overcome the disadvantages of organic liquid electrolytes and all-solid electrolytes, and make better use in the next generation of safe and high energy rechargeable lithium metal batteries. Herein, an effective ionic liquid gel polymer electrolyte is simply prepared using core-shell structured SiO2 nanoparticles as functional fillers, which is fabricated by controlled reaction conditions, its structure and purity are characterized. The shell layers of SiO2-PAA@Li as the lithium ion sources increase both ionic conductivity and lithium transference number of the electrolyte. Especially, it was found to improve thermal stability and increase compatibility between electrolyte and lithium electrode due to the intrinsic characteristics of the silica core structure. More importantly, the morphological analysis of the cycled lithium anode reveals that lithium dendrites growth during cycling can be inhibited by a stable solid electrolyte interphase. For further illustration, the solid-state lithium battery of LiFePO4/Li with this type electrolyte delivers stable charge/discharge profiles and satisfactory performance, determining the important role on the overall electrochemical properties of its unique structural design. These desirable results reveal that the composite gel polymer electrolytes have great potential for safe, stable even high power rechargeable Li metal batteries.

Pulsed discharge of printed secondary Zn-MnO2 batteries for IoT and wearable devices

This paper reports the manufacturing and testing via pulsed discharging of printed secondary Zn-MnO2 batteries with ionic liquid gel polymer electrolyte (GPE) for IoT and wearable devices. Printed cells under constant current discharge conditions demonstrated average DC internal resistances of 175-225 Ω/cm2. Printed cells under pulsed discharge current demonstrated decreasing internal resistances with increasing cycle number, reaching an average plateau of 125 Ω/cm2 after 50 cycles and remaining beyond 650 cycles. This work improves upon manufacturing methods reported at PowerMEMS 2015 and investigates system-level compatibility with IoT and wearable devices.