| 1. |
- Huang, Yu-Kai, et al.
(författare)
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Diffusion-Controlled Lithium Trapping in Graphite Composite Electrodes for Lithium-Ion Batteries
- 2022
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Ingår i: ADVANCED ENERGY AND SUSTAINABILITY RESEARCH. - : John Wiley & Sons. - 2699-9412. ; 3:8
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Tidskriftsartikel (refereegranskat)abstract
- Although graphite-based composite electrodes currently are widely used as negative electrodes in lithium-ion batteries due to their good cycle performances, improvements of their long-time cycling stability are still desirable. Herein, a series of lithium-metal half-cell experiments is performed to demonstrate that the diffusion-controlled lithium-trapping effect constitutes an additional, and so far, largely unrecognized, aging mechanism for graphite-based electrodes. This trapping effect, which stems from incomplete delithiation due to diffusion-controlled redistribution of intercalated lithium in graphite, is shown to account for around 30% of the total accumulated capacity loss during long-time cycling. The trapping effect is caused by the concentration gradients present at the end of the lithiation steps as these gradients result in lithium (i.e., coupled Li+ and e(-)) diffusion in the electrodes. As a result, a small fraction of the lithium becomes inaccessible on the timescale of the subsequent delithiation step. The results, however, also show that the inclusion of constant-voltage delithiation steps can increase the delithiation efficiency and decrease the influence of the lithium-trapping effect. This work consequently demonstrates that diffusion-controlled lithium-trapping effects need to be considered when trying to increase the lifetimes of graphite-based electrodes.
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| 2. |
- Khan, Ziyauddin, et al.
(författare)
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Water-in-Polymer Salt Electrolyte for Slow Self-Discharge in Organic Batteries
- 2022
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Ingår i: Advanced Energy and Sustainability Research. - : WILEY. - 2699-9412. ; 3:1
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Tidskriftsartikel (refereegranskat)abstract
- In electrochemical energy storage devices (ESDs), organic electrolytes are typically used for wide operational potential window, yet they suffer with cost, environmental, flammability issues, and low ionic conductivity when compared with water-based electrolytes. Hence, for large-scale applications that require high power and safety, presently there is no true solution. Though water-based electrolytes have higher ionic conductivities, and are cost-effective and nonflammable, their high self-discharge rate with organic/carbon-based electrodes impedes their commercialization. It is found out that highly concentrated polymer electrolytes on the concept of "water-in-salt electrolyte" lead to extremely low leakage current within the electrochemical stability window (ESW) of water, thus solving the issue of self-discharge in organic/carbon-based ESDs. Herein, potassium polyacrylate (PAAK) is prepared as "water-in-polymer salt electrolyte" (WIPSE) and tested for one of most abundant wood-based biopolymer lignin and polyimide as positive and negative electrodes, respectively, in both half-cell and full-cell. The device shows an open-circuit voltage drops <0.45V in 100h setting a record for organic batteries using aqueous electrolyte. The high ionic conductivity (40-120mScm(-1)) nonflammability of PAAK with high ESW (3.1V) opens a new direction for truly safe, sustainable, and high power (6.8kWkg(-1)) organic ESD manufactured by printing technologies.
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| 3. |
- Kotronia, Antonia, et al.
(författare)
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Ternary Ionogel Electrolytes Enable Quasi-Solid-State Potassium Dual-Ion Intercalation Batteries
- 2022
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Ingår i: Advanced Energy and Sustainability Research. - : John Wiley & Sons. - 2699-9412. ; 3:1, s. 2100122-
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Tidskriftsartikel (refereegranskat)abstract
- A dual-ion battery (DIB) is an emerging technology destined for use in stationary energy storage applications. Most DIB prototypes use expensive salt-concentrated liquid electrolytes to ensure sufficient ion supply and an electrochemical stability window beyond 4.5 V, which is required for anion intercalation in graphite. Herein, the design of a compact quasi-solid-state potassium-based DIB is introduced using ternary ionogel electrolytes (t-IGEs) prepared from a potassium salt, an ionic liquid, and a poly(ionic liquid). Among a series of combinations, the t-IGE with optimum mechanical property, thermal stability (>200 °C), and electrochemical performance consists of 30% salt, 28% ionic liquid, and 42% poly(ionic liquid). With ionic conductivity ranging from 0.1 to 1 mS cm−1 at 30–100°C and an electrochemical stability window within 0.5–5.0 V versus K+/K, the t-IGE is suited for practical MoS2–graphite KDIBs. Infusing the ionogel in plain-weave glass fiber fabrics (≈40 μm thick) further enables the design of more compact KDIBs in which a significant reduction (≈64%) in electrolyte thickness is achieved. The cells are able to deliver specific capacities varying from 80 to 25 mAh g−1 at 10 to 160 mA g−1, with CEs ranging from ≈90% to 100%.
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| 4. |
- Kumar, Divyaratan, et al.
(författare)
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Self-Discharge in Batteries Based on Lignin and Water-in-Polymer Salt Electrolyte
- 2022
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Ingår i: Advanced Energy and Sustainability Research. - : Wiley. - 2699-9412. ; 3:10
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Tidskriftsartikel (refereegranskat)abstract
- Lignin, the most abundant biopolymer on earth, has been explored as an electroactive material in battery applications. One essential feature for such lignin-based batteries to reach successful usage and implementation, e.g., large-scale stationary grid applications, is to have slow self-discharge characteristics on top of the essential safety and life-cycle properties. Water-in-polymer salt electrolytes (WIPSEs) have been demonstrated as an attractive route to solve this issue; however, little has been done to understand the fundamentals of actual self-discharge mechanisms. Herein, the impact of some critical chemical and physical parameters (pH, dissolved oxygen, viscosity, and cutoff potential) on self-discharge of batteries based on WIPSE and lignin has been investigated. The pH range is crucial as there is an interplay between long-term stability and high energy density. Indeed, lignin derivatives typically store relatively more charge in acidic media but later promote corrosion affecting device stability. A robust and high-performing organic battery, incorporating potassium polyacrylate as WIPSE, is demonstrated, which expresses good self-discharge behavior for a broad range of pH and with little impact on the atmosphere used for manufacturing. It is believed that the investigation will provide critical insights to the research community to promote the advancement of printed large-scale energy storage devices.
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| 5. |
- Lander, Sanna, 1990-, et al.
(författare)
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Sulfonated Cellulose Membranes Improve the Stability of Aqueous Organic Redox Flow Batteries
- 2022
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Ingår i: Advanced Energy and Sustainability Research. - : Wiley. - 2699-9412. ; 3:9
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Tidskriftsartikel (refereegranskat)abstract
- The drawbacks of current state-of-the-art selective membranes, such as poor barrier properties, high cost, and poor recyclability, limit the large-scale deployment of electrochemical energy devices such as redox flow batteries (RFBs) and fuel cells. In recent years, cellulosic nanomaterials have been proposed as a low-cost and green raw material for such membranes, but their performance in RFBs and fuel cells is typically poorer than that of the sulfonated fluoropolymer ionomer membranes such as Nafion. Herein, sulfonated cellulose nanofibrils densely cross-linked to form a compact sulfonated cellulose membrane with limited swelling and good stability in water are used. The membranes possess low porosity and excellent ionic transport properties. A model aqueous organic redox flow battery (AORFB) with alizarin red S as negolyte and tiron as posolyte is assembled with the sulfonated cellulose membrane. The performance of the nanocellulose-based battery is superior in terms of cyclability in comparison to that displayed by the battery assembled with commercially available Nafion 115 due to the mitigation of crossover of the redox-active components. This finding paves the way to new green organic materials for fully sustainable AORFB solutions.
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| 6. |
- Sun, Bianjing, et al.
(författare)
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Sustainable Amylopectin-Derived Miniwindmills for Moisture-Induced Electric Generation
- 2022
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Ingår i: Advanced Energy and Sustainability Research. - : Wiley. - 2699-9412. ; 3:11
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Tidskriftsartikel (refereegranskat)abstract
- Capturing energy from the environment provides the hope for clean energy and enables the formation of self-powered systems. Nanostructured functional materials can interact with water to generate electrical energy, greatly expanding the technical capabilities of water energy harvesting, while those derived from sustainable biomass for this purpose are still in the infancy. Herein, a series of thin self-standing amylopectin-derived membranes of several micrometers can output hydrovoltaic electric energy in the ambient environment. One single-unit flat device (around 0.78 cm2) can generate an instant voltage of up to 0.95 V from high ambient humidity. The underlying mechanism for generating electricity from amylopectin-derived membranes is attributed to the fast adsorption and desorption of water molecules on the membrane surface based on the results of dynamic vapor sorption. Novel moisture-induced miniwindmills as electric generators are fabricated, thanks to these outstanding features such as being self-standing, flexible, lightweight, and having ease of scale production. Such miniwindmill devices with a membrane layer thickness of ≈10 μm can be used to harvest energy with a sustained voltage of around 0.45 V from ambient environment. These results pave the way for developing energy-harvesting powerful minisized devices that exploit water gradients prevalent in nature with biomass materials.
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| 7. |
- Zheng, Wei, et al.
(författare)
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Aqueous Electrolytes, MXene-Based Supercapacitors and Their Self-Discharge
- 2022
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Ingår i: Advanced Energy and Sustainability Research. - : Wiley. - 2699-9412. ; 3:2
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Tidskriftsartikel (refereegranskat)abstract
- Significant efforts have been dedicated to developing Ti3C2Tz-based MXene aqueous supercapacitors (SCs) with improved energy and power densities. Notably less research has been devoted to an equally important characteristic of aqueous SCs, viz. self-discharge (SD). The SD rates are rarely reported despite their crucial importance from a practical point of view. Herein, the SD rates in four different aqueous electrolytes: H2SO4, KOH, LiCl, and LiBr in Ti3C2Tz-based aqueous SCs are compared. For the latter two, the SD rates vary as a function of salt concentration in the electrolytes with higher LiCl or LiBr concentrations having the lowest SD rates, viz. 78.3% and 81.5% in 14m LiCl and LiBr, respectively, after 10h. Further, the influence of dissolved oxygen and the purities of the starting powders are examined, and it is concluded that parasitic reactions, including oxygen, are responsible for the SD.
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