A new double layer super-capacitor made by free-standing activated carbon membranes and highly concentrated potassium acetate solutions

Tribbia, Michele; Pianta, Nicolò; Brugnetti, G; Lorenzi, Roberto; Ruffο, Riccardo

doi:10.1016/j.electacta.2020.137323

Cited by 13 publications

(14 citation statements)

References 17 publications

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“…The resulting slurries were deposited on aluminium foils (30 μm of thickness) with different thicknesses (5, 10 and 30 mils), then dried under vacuum at 80°C overnight and pressed with a calender. Self-standing high-load electrodes were prepared following a previously reported route [21] by grounding NVPF together with Super P conductive carbon in a mortar and mixing the obtained powder with a suspension of PTFE in water (Sigma-Aldrich, 60 wt%) to obtain a homogenous dough. The amount of suspension was calculated in order to have the same ratio of active material/binder as for the supported electrode, i.e.…”

Section: Methodsmentioning

confidence: 99%

Cycling properties of Na3V2(PO4)2F3 as positive material for sodium-ion batteries

Pianta

Locatelli

Ruffο

2021

Ionics

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The research into sodium-ion battery requires the development of high voltage cathodic materials to compensate for the potential of the negative electrode materials which is usually higher than the lithium counterparts. In this framework, the polyanionic compound Na3V2(PO4)2F3 was prepared by an easy-to-scale-up carbothermal method and characterized to evaluate its electrochemical performances in half cell vs. metallic sodium. The material shows a specific capacity (115 mAh g−1) close to the theoretical limit, good coulombic efficiency (>99%) and an excellent stability over several hundred cycles at high rate. High-loading free-standing electrodes were also tested, which showed interesting performances in terms of areal capacity and cyclability.

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Section: Methodsmentioning

confidence: 99%

Cycling properties of Na3V2(PO4)2F3 as positive material for sodium-ion batteries

Pianta

Locatelli

Ruffο

2021

Ionics

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“…[21] Moreover, the very low solubility and the possibility to modify the intercalation potential by tuning the chemical composition, so matching the bounds of electrolyte ESW, make NASICON compounds an ideal choice as electrode materials. [18] Among them, LiTi 2 (PO 4 ) 3 (LTP), with a relatively low average operative potential (0 V vs RHE when Na + is intercalating) and an achievable capacity of up to 100-110 mAh g À 1 in aqueous electrolytes, [22] can be considered of particular interest for use in WISE media. As already demonstrated in the literature, the low electrical conductivity of this NASICON phase requires a carbon shell around the active material particles to enable good electrochemical performances.…”

Section: Introductionmentioning

confidence: 99%

“…In this framework, Sodium (Na) Super Ionic CONductor (NASICON) compounds offer significant advantages due to their stable structure and large ionic channels with accessible sites for highly efficient ions insertion‐extraction [21] . Moreover, the very low solubility and the possibility to modify the intercalation potential by tuning the chemical composition, so matching the bounds of electrolyte ESW, make NASICON compounds an ideal choice as electrode materials [18] . Among them, LiTi 2 (PO 4 ) 3 (LTP), with a relatively low average operative potential (0 V vs RHE when Na + is intercalating) and an achievable capacity of up to 100–110 mAh g −1 in aqueous electrolytes, [22] can be considered of particular interest for use in WISE media.…”

Section: Introductionmentioning

confidence: 99%

Electrochemical Impedance Spectroscopy for Electrode Process Evaluation: Lithium Titanium Phosphate in Concentrated Aqueous Electrolyte

et al. 2023

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Aqueous electrolytes in the form of highly concentrated solutions stand as a viable alternative to the organic counterpart as battery electrolytes thanks to the low flammability, toxicity, cost and large availability, while keeping good potential windows. In this work, a half‐cell constituted of lithium titanium phosphate in a binary aqueous solution of sodium acetate (7 mol kg−1) and potassium acetate (20 mol kg−1) as a promising anode for sodium‐ion batteries is characterized with constant current, static and dynamic electrochemical impedance spectroscopy to reveal its thermodynamic and kinetic properties. The experiments permit to withdraw some information on the thermodynamics (activation energy of processes) and kinetics (processes’ parameters evolution) of the system. Physical information was extracted from impedance spectra with mathematical regression of a porous electrode intercalation model available in literature using an innovative procedure of batch‐fitting of a complete set of spectra at once. The advantage and shortcoming on using impedance in battery‐development is discussed.

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“…Examples of cost-effective, highly soluble, and widely available salts are LiCl, CH3COONa (NaAc), and CH3COOK (KAc). In particular, KAc has been recently investigated by our group 17 , proposed in potassium ion batteries (KIBs), and employed in supercapacitors 18 . Moreover, KAc can be coupled with Li, Na and Zn salts to achieve binary electrolytes with concentrations above 20 mol kg -1 19 .…”

Section: Introductionmentioning

confidence: 99%

“…In this framework, NASICON compounds offer significant advantages owing to their stable structure and large ionic channels with accessible sites for highly efficient ions insertion-extraction 21 . Moreover, the very low solubility and the possibility to modify the intercalation potential by tuning the chemical composition, so matching the cell voltage with the electrolyte ESW, make NASICON compounds an ideal choice as electrode materials 18 .…”

Section: Introductionmentioning

confidence: 99%

The properties of highly concentrated aqueous CH3COOK/Na binary electrolyte and its use in sodium-ion batteries

Khalid

Pianta

Bonizzoni

et al. 2021

Preprint

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Highly concentrated aqueous binary solutions of acetate salts are emerging as promising systems for advanced energy storage applications. Together with superior solubility of CH3COOK helpful in achieving water-in-salt electrolyte concentrations, the presence of CH3COOLi or CH3COONa permits intercalation of desired cations in electrode crystalline phases. Although these systems have captured profound scientific attention in recent years, a fundamental understanding of their physicochemical properties is still lacking. In this work, the thermal, rheological, transport, and electrochemical properties for a series of solutions comprising of 20 mol kg-1 of CH3COOK with different concentrations of CH3COONa are reported and discussed. The most concentrated solution, i.e., 20 mol kg-1 of CH3COOK with 7 mol kg-1 of CH3COONa came out to be the best in terms of a compromise between transport properties and electrochemical stability window. Such a solution has a conductivity of 21.2 mS cm-1 at 25°C and shows a stability window up to 3 V in “ideal” conditions, i.e., using small surface area and highly electrocatalytic electrode in a flooded cell. As a proof of concept of using this solution in sodium-ion batteries, carbon-coated LiTi2(PO4)3 (NASICON) demonstrated the ability to reversibly insert and de-insert Na+ ions at about -0.7 V vs. SHE with a first cycle anodic capacity of 85 mAh g-1, average charge efficiency of 96% at low current and a 90% capacity retention after 60 cycles. The very good kinetic properties of the interface are also demonstrated by the low value of activation energy for the charge transfer process (0.12 eV).

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A new double layer super-capacitor made by free-standing activated carbon membranes and highly concentrated potassium acetate solutions

Cited by 13 publications

References 17 publications

Cycling properties of Na3V2(PO4)2F3 as positive material for sodium-ion batteries

Cycling properties of Na3V2(PO4)2F3 as positive material for sodium-ion batteries

Electrochemical Impedance Spectroscopy for Electrode Process Evaluation: Lithium Titanium Phosphate in Concentrated Aqueous Electrolyte

The properties of highly concentrated aqueous CH3COOK/Na binary electrolyte and its use in sodium-ion batteries

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