| 1. |
- Khan, Ziyauddin, et al.
(författare)
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Does Water-in-Salt Electrolyte Subdue Issues of Zn Batteries?
- 2023
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Ingår i: Advanced Materials. - : WILEY-V C H VERLAG GMBH. - 0935-9648 .- 1521-4095. ; 35:36
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Forskningsöversikt (refereegranskat)abstract
- Zn-metal batteries (ZnBs) are safe and sustainable because of their operability in aqueous electrolytes, abundance of Zn, and recyclability. However, the thermodynamic instability of Zn metal in aqueous electrolytes is a major bottleneck for its commercialization. As such, Zn deposition (Zn2+ & RARR; Zn(s)) is continuously accompanied by the hydrogen evolution reaction (HER) (2H(+) & RARR; H-2) and dendritic growth that further accentuate the HER. Consequently, the local pH around the Zn electrode increases and promotes the formation of inactive and/or poorly conductive Zn passivation species (Zn + 2H(2)O & RARR; Zn(OH)(2) + H-2) on the Zn. This aggravates the consumption of Zn and electrolyte and degrades the performance of ZnB. To propel HER beyond its thermodynamic potential (0 V vs standard hydrogen electrode (SHE) at pH 0), the concept of water-in-salt-electrolyte (WISE) has been employed in ZnBs. Since the publication of the first article on WISE for ZnB in 2016, this research area has progressed continuously. Here, an overview and discussion on this promising research direction for accelerating the maturity of ZnBs is provided. The review briefly describes the current issues with conventional aqueous electrolyte in ZnBs, including a historic overview and basic understanding of WISE. Furthermore, the application scenarios of WISE in ZnBs are detailed, with the description of various key mechanisms (e.g., side reactions, Zn electrodeposition, anions or cations intercalation in metal oxide or graphite, and ion transport at low temperature).
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| 2. |
- Khan, Ziyauddin, et al.
(författare)
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Mass Transport in “Water-in-Polymer Salt” Electrolytes
- 2023
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Ingår i: Chemistry of Materials. - : American Chemical Society (ACS). - 0897-4756 .- 1520-5002. ; 35, s. 6382-6395
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Tidskriftsartikel (refereegranskat)abstract
- “Water-in-polymer salt” electrolytes (WiPSEs) based on potassium polyacrylate (PAAK) belong to a new family of “water-in-salt” electrolytes that is envisioned as a potential solution for large-scale supercapacitors to balance the electric grid at short time scales. The WiPSEs display a broad electrochemical stability window up to 3 V, yet they are nonflammable and provide high ionic conductivity (100 mS/cm) as required in high-power devices. However, the transport of matter in PAAK-based WiPSEs has not been studied. In this work, we have extensively characterized PAAK by spectroscopic methods such as Raman spectroscopy and NMR diffusometry to determine the state of water and elucidate the mechanism of ionic transport as well as its interplay with water and polymer chain dynamics, which reveals that a significant proportion of the transport in WiPSEs is attributed to hydrated cations. The results are further supported by molecular dynamics (MD) simulations. Finally, the potential of WiPSEs based on PAAK is demonstrated in an activated carbon-based supercapacitor operating up to 2 V with reasonable self-discharge. This proof of concept shows promise for low-cost and large-scale supercapacitors.
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| 3. |
- Kim, Nara, et al.
(författare)
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An intrinsically stretchable symmetric organic battery based on plant-derived redox molecules
- 2023
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Ingår i: Journal of Materials Chemistry A. - : Royal Society of Chemistry. - 2050-7488 .- 2050-7496. ; 11:46, s. 25703-25714
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Tidskriftsartikel (refereegranskat)abstract
- Intrinsically stretchable energy storage devices are essential for the powering of imperceptible wearable electronics. Organic batteries based on plant-derived redox-active molecules can offer critical advantages from a safety, sustainability, and economic perspective, but such batteries are not yet available in soft and stretchable form factors. Here we report an intrinsically stretchable organic battery made of elastomeric composite electrodes formulated with alizarin, a natural dye derived from the plant Rubia tinctorum, whose two quinone motifs enable its uses in both positive and negative electrodes. The quaternary biocomposite electrodes possess excellent electron-ion conduction/coupling and superior stretchability (>300%) owing to self-organized hierarchical morphology. In a full-cell configuration, its energy density of 3.8 mW h cm−3 was preserved at 100% strain, and assembled modules on stretchy textiles and rubber gloves can power integrated LEDs during various deformations. This work paves the way for low-cost, eco-friendly, and deformable batteries for next generation wearable electronics.
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| 4. |
- Kumar, Divyaratan, 1995-
(författare)
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Water-in-polymer Salt Electrolyte (WIPSE) for Sustainable Lignin Batteries
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Organic electrolytes are widely used in energy storage technologies, but they are known to have safety, cost, and eco friendliness concerns. Water based electrolytes do not have those issues but are limited by their narrow range potential range of operation to 1.2V. Above that voltage, significant side reactions lead to gas evolution, side reaction and high selfdischarge rate in organic batteries. Because of their superior ionic conductivities, which are critical for reducing device resistance and improving power; as well as their cost-effective ness and non-flammability, researchers have had a second look at water-based electrolyte and found out that super concentrated aqueous solutions behave differently, and their electrochemical stability window can be widened.In this thesis, polyacrylate (PAAK) based "water in polymer salt" electrolyte (WIPSE) has been identified as a promising solution for large-scale energy storage devices. This new family of "water in salt" electrolytes offers a broad electrochemical stability window of up to 3V, a high ionic conductivity (100 mS/cm) and is non-flammable, making it ideal for high power electrochemical storage devices. However, little is known about the matter transport in PAAK based WIPSE and in "water in salt" electrolytes in general. Therefore, this thesis also aims to investigate the properties of PAAK using spectroscopic techniques such as Raman spectroscopy and diffusion NMR to understand the behavior of water and the mechanism of ionic transport in relation to water and polymer chain dynamics. Since the electrolyte only transports cations, it is suitable for use in "cation rocking chair" batteries that utilize two types of polymeric quinones, lignin, and polyimide redox polymers, as positive and negative electrodes, respectively. The electrochemically active redox polymers with K+ ions at neutral pH are ions at neutral pH are advantageous for avoiding corrosion in metal collectors. Further for understanding the fundamental of self-discharge mechanism, the impact of some critical chemical and physical parameters on performance of lignin-based batteries have been investigated.The final chapter of the thesis introduces a novel approach to address the challenges associated with Zn-ion batteries by utilizing the "water-inpolymer salt" electrolyte concept modified by salt additives. The goal is to enable the use of lignin-carbon (L-C) electrodes in a Zinc battery. Lignin, carbon and zinc are among the most affordable, environmentally friendly and sustainable options for energy storage for energy storage. By incorporating WIPSE electrolytes these batteries can offer additional benefits, such as improved safety and the prevention of dendrite formation. Our findings demonstrate that acrylate groups in the electrolyte stabilize the flux on the zinc electrode surface, promoting parallel deposition and significantly reducing dendritic formation through vertical growth. The assembled Zn-lignin battery delivers a maximum energy of 23 Wh/kg and a maximum power of 610 W/kg, with an exceptional 82% retention after 8000 cycles. With the reduced expected environmental impact of green and the cost- effectiveness of these polymer electrolytes, the resulting battery shows great promise in the battery market. Its emergence has opened a new avenue in the pursuit of safe and efficient batteries, which has been a major area of focus within the energy storage industry.
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| 5. |
- Kumar, Divyaratan, 1995-, et al.
(författare)
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Zinc salt in "Water-in-Polymer Salt Electrolyte" for Zinc-Lignin Batteries: Electroactivity of the Lignin Cathode
- 2023
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Ingår i: ADVANCED SUSTAINABLE SYSTEMS. - : WILEY-V C H VERLAG GMBH. - 2366-7486. ; 7:4
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Tidskriftsartikel (refereegranskat)abstract
- Zn-ion batteries are one of the hot candidates for low-cost and sustainable secondary batteries. The hydrogen evolution and dendritic growth upon zinc deposition are todays challenges for that technology. One of the new strategies to cope with these issues is to use "water-in-salt" electrolyte (WISE), that is, super concentrated aqueous electrolytes, to broaden its electrochemical stability window (ESW), suppressing hydrogen evolution reaction (HER), and perturbing the dendritic growth. Herein, this work proposes to use "water-in-polymer salt" electrolyte (WIPSE) concept to mitigate the challenges with Zn ion batteries and bring this technology toward one of the cheapest, greenest, and most sustainable electrodes: Lignin-carbon (L-C) electrode. Potassium polyacrylate (PAAK) as WISE bears out as better electrolyte for L-C electrodes in terms of self-discharge, cyclic stability, and specific capacity compared to conventional electrolyte based on chemically cousin molecule potassium acetate. Zinc bis(trifluoromethanesulfonyl) imide (Zn(TFSI)(2)) added into WIPSE shows deposition and dissolution of Zn in Zn//Zn symmetric cell suggesting that Zn2+ are moving into the polyanionic network. Furthermore, the added bis (trifluor omethanesul fonyl) imide (TFSI-) metal salts trigger a approximate to 40% enhancement of the capacity of L-C electrode. These results show a new promising direction toward the development of cost-effective and sustainable Zn-lignin batteries.
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| 6. |
- Patil, Sayali Ashok, et al.
(författare)
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2D Zinc Oxide - Synthesis, Methodologies, Reaction Mechanism, and Applications
- 2023
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Ingår i: Small. - : WILEY-V C H VERLAG GMBH. - 1613-6810 .- 1613-6829. ; 19:14
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Forskningsöversikt (refereegranskat)abstract
- Zinc oxide (ZnO) is a thermally stable n-type semiconducting material. ZnO 2D nanosheets have mainly gained substantial attention due to their unique properties, such as direct bandgap and strong excitonic binding energy at room temperature. These are widely utilized in piezotronics, energy storage, photodetectors, light-emitting diodes, solar cells, gas sensors, and photocatalysis. Notably, the chemical properties and performances of ZnO nanosheets largely depend on the nano-structuring that can be regulated and controlled through modulating synthetic strategies. Two synthetic approaches, top-down and bottom-up, are mainly employed for preparing ZnO 2D nanomaterials. However, owing to better results in producing defect-free nanostructures, homogenous chemical composition, etc., the bottom-up approach is extensively used compared to the top-down method for preparing ZnO 2D nanosheets. This review presents a comprehensive study on designing and developing 2D ZnO nanomaterials, followed by accenting its potential applications. To begin with, various synthetic strategies and attributes of ZnO 2D nanosheets are discussed, followed by focusing on methodologies and reaction mechanisms. Then, their deliberation toward batteries, supercapacitors, electronics/optoelectronics, photocatalysis, sensing, and piezoelectronic platforms are further discussed. Finally, the challenges and future opportunities are featured based on its current development.
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| 7. |
- Rahmanudin, Aiman, et al.
(författare)
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Sustainable stretchable batteries for next-generation wearables
- 2023
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Ingår i: Journal of Materials Chemistry A. - : ROYAL SOC CHEMISTRY. - 2050-7488 .- 2050-7496. ; 11:42, s. 22718-22736
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Tidskriftsartikel (refereegranskat)abstract
- Next-generation wearables will interface intimately with the human body either on-skin, implanted or woven into clothing. This requires electrical components that match the mechanical properties of biological tissues - stretchability (up to 60% strain) and softness (Youngs modulus of similar to 1 kPa to 1 MPa). As wearables become increasingly complex, the energy and mechanical requirements will increase, and an integrated power supply unit such as a soft and stretchable battery is needed to achieve autonomy and wireless operation. However, two key challenges remain for current stretchable battery technology: the mechanical performance (softness and stretchability) and its relation to the size and charge storage capacity (challenge I), and the sustainability and biocompatibility of the battery materials and its components (challenge II). Integrating all these factors into the battery design often leads to a trade-off between the various properties. This perspective will evaluate current strategies for achieving sustainable stretchable batteries and provide a discussion on possible avenues for future research. Stretchable battery technology still faces several challenges to progress the development of next-generation wearables. This perspective will evaluate current strategies and provide a discussion on possible avenues for future research.
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| 8. |
- Sultana, Ayesha, et al.
(författare)
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The Origin of Thermal Gradient-Induced Voltage in Polyelectrolytes
- 2023
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Ingår i: Small. - : WILEY-V C H VERLAG GMBH. - 1613-6810 .- 1613-6829.
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Tidskriftsartikel (refereegranskat)abstract
- Ionic thermoelectric materials can generate large thermal voltages under temperature gradients while also being low-cost and environmentally friendly. Many electrolytes with large Seebeck coefficients are reported in recent years, however, the mechanism of the thermal voltage is remained elusive. In this work, three types of polyelectrolytes are studied with different cations and identified a significant contribution to their thermal voltage originating from a concentration gradient. This conclusion is based on studies of the loss and gain of water upon temperature changes, variations in conductivity with water content and temperature, and the voltages induced by changes in water content. The results are analyzed by the "hopping mode" dynamics of charge transport in electrolytes. The hydration of different cations influences the water concentration gradient, which affects the barrier height and ion-induced potential in the electrodes. This work shows that the hydro-voltage in ionic thermoelectric devices can be one order of magnitude larger than the contribution from thermodiffusion-induced potentials, and becomes the main contributor to energy harvesting when implemented into ionic thermoelectric supercapacitors. Together with the rationalized theoretical discussion, this work clarifies the mechanism of thermal voltages in electrolytes and provides a new path for the development of ionic thermoelectric materials. The thermal voltage of polyelectrolyte films largely depends on the water concentration gradient under a temperature difference, which can be optimized to promote the generated total voltage up to over 30 mV K-1.image
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