| 1. |
- Chodankar, N. R., et al.
(författare)
-
Solution-free self-assembled growth of ordered tricopper phosphide for efficient and stable hybrid supercapacitor
- 2021
-
Ingår i: Energy Storage Materials. - : Elsevier B.V.. - 2405-8289 .- 2405-8297. ; 39, s. 194-202
-
Tidskriftsartikel (refereegranskat)abstract
- Herein, a solution-free dry strategy for the growth of self-assembled ordered tricopper phosphide (Cu3P) nanorod arrays is developed and the product is employed as a high-energy, stable positive electrode for a solid-state hybrid supercapacitor (HSC). The ordered Cu3P nanorod arrays grown on the copper foam deliver an excellent specific capacity of 664 mA h/g with an energy efficiency of 88% at 6 A/g and an ultra-long cycling stability over 15,000 continuous charge–discharge cycles. These electrochemical features are attributed to the ordered growth of the Cu3P nanorod arrays, which offers a large number of accessible electroactive sites, a reduced number of ion transfer paths, and reversible redox activity. The potential of the Cu3P nanorod arrays is further explored by engineering solid-state HSCs in which the nanorods are paired with an activated carbon-based negative electrode. The constructed cell is shown to convey a specific energy of 76.85 Wh/kg at a specific power of 1,125 W/kg and an 88% capacitance retention over 15,000 cycles. Moreover, the superior energy storing and delivery capacity of the cell is demonstrated by an energy efficiency of around 65%. The versatile solution-free dry strategies developed here pave the way towards engineering a range of electrode materials for next-generation energy storage systems. © 2021 Elsevier B.V.
|
|
| 2. |
- El Ghazaly, Ahmed, et al.
(författare)
-
Enhanced supercapacitive performance of Mo1.33C MXene based asymmetric supercapacitors in lithium chloride electrolyte
- 2021
-
Ingår i: Energy Storage Materials. - : Elsevier. - 2405-8289 .- 2405-8297. ; 41, s. 203-208
-
Tidskriftsartikel (refereegranskat)abstract
- Two-dimensional (2D) Mo1.33C MXene renders great potential for energy storage applications and is mainly studied in the sulfuric acid (H2SO4) electrolyte. However, H2SO4 limits the electrode potential to 0.9 V for symmetric devices and 1.3 V for asymmetric devices. Herein, we explore the electrochemical behavior of Mo1.33C MXene in LiCl electrolyte. In comparison to H2SO4, LiCl electrolyte is a neutral salt with high solubility at room temperature and low hazardousness. The analysis shows a volumetric capacitance of 815 Fcm(-3) at a scan rate of 2 mVs(-1) with a large operating potential window of -1.2 to +0.3V (vs. Ag/AgCl). This is further exploited to construct MXene-based asymmetric supercapacitors Mo1.33C//MnxOn, and the electrochemical performance is evaluated in 5M LiCl electrolyte. Owing to the wide voltage widow of the Mo1.33C//MnxOn devices (2V) and high packing density of the electrodes, we have achieved a volumetric energy density of 58 mWh/cm(3), a maximum power density of 31 Wcm(-3) and retained 92% of the initial capacitance after 10,000 charge/discharge cycles at 10 A g(-1). One of the main value propositions of this work, aside from the high energy density, is the outstanding columbic efficiency (100%), which ensures excellent cyclic stability and is highly desirable for practical applications.
|
|
| 3. |
- Li, Changjiu, et al.
(författare)
-
Multifunctional surfactants for synthesizing high-performance energy materials
- 2021
-
Ingår i: Energy Storage Materials. - : Elsevier. - 2405-8289 .- 2405-8297. ; 43, s. 1-19
-
Tidskriftsartikel (refereegranskat)abstract
- Due to a steady increase of electrical energy consumption, the demand for high-performance energy storage materials becomes more urgent than ever. Compared to other synthetic technologies, surfactant templating method offers the most efficient way to improve electrochemical performances of energy storage materials. In the synthesis of energy storage materials prepared, various surfactants are often used and play a crucial role in determining the properties of final products. Multifunctional surfactants can effectively tailor and control particle size, crystallinity, morphology, porosity, structure and composition of energy storage materials, achieving significant enhancement in rate capability and cycle stability. Herein, we summarize various surfactants, including classic alkyl-based surfactants, polymers, biological ligands and other surface active molecules. This review highlights the essential roles of surfactants, working as structure-directing agents, carbon sources, porogens and stabilizer agents, etc., in controlling nanostructure of energy storage materials and improving their properties. For different batteries (such as lithium-ion batteries, sodium-ion batteries, lithium-sulfur batteries, lithium-oxygen batteries and alkaline batteries) and supercapacitors, similarities and differences in surfactant mechanism, functions, electrochemical performances of the synthesized materials, challenges and opportunities are discussed as well. To facilitate further development of surfactant template method, some future research trends and directions are finally put forward.
|
|
| 4. |
- Majumder, M., et al.
(författare)
-
Two-dimensional Conducting Metal-Organic Frameworks Enabled Energy Storage Devices
- 2021
-
Ingår i: Energy Storage Materials. - : Elsevier B.V.. - 2405-8289 .- 2405-8297. ; 37, s. 396-416
-
Tidskriftsartikel (refereegranskat)abstract
- Two-dimensional (2D) conducting metal-organic frameworks (MOFs) is an emerging family of porous materials that have attracted a great attention due to their outstanding inherent properties such as hierarchical porosity, diverse architectures with high surface area and excellent electrical conductivity. These unique features make them ideal candidates for electrochemical energy storage technologies. This review highlights the key innovations on 2D conducting MOFs with emphasis on the design and synthesis strategies, and their potential applications in energy storage systems. Several recent breakthrough examples of 2D conducting MOFs with enhanced electrochemical performances are outlined. The review further extends the discussion on the significance of Nuclear Magnetic Resonance Spectroscopy (NMR) to understand the charge storage kinetics and their impact on structural implications of the materials. The elucidation of structure-property-performance relationship will further guide the development of new architectures of 2D conducting MOFs for the high-performance energy storage devices. © 2021
|
|
| 5. |
- Pham, H. D., et al.
(författare)
-
Large interspaced layered potassium niobate nanosheet arrays as an ultrastable anode for potassium ion capacitor
- 2021
-
Ingår i: Energy Storage Materials. - : Elsevier B.V.. - 2405-8289 .- 2405-8297. ; 34, s. 475-482
-
Tidskriftsartikel (refereegranskat)abstract
- Potassium-ion battery (KIB) is a promising technology for large-scale energy storage applications due to their low cost, theoretically high energy density and abundant resources. However, the development of KIBs is hindered by the sluggish K+ transport kinetics and the structural instability of the electrode materials during K+ intercalation/de-intercalation. In the present investigation, we have designed a potassium-ion capacitor (KIC) using layered potassium niobate (K4Nb6O17, KNO) nanosheet arrays as anode and orange-peel derived activated carbons (OPAC) as fast capacitive cathode materials. The systematic electrochemical analysis with the ex-situ characterizations demonstrates that KNO-anode exhibits highly stable layered structure with excellent reversibility during K+ insertion/de-insertion. After optimization, the fabricated KNO//OPAC delivers both a high energy density of 116 Wh/kg and high power density of 10,808 W/kg, which is significantly higher than other similar hybrid devices. The cell also displays long term cycling stability over 5000 cycles, with 87 % of capacity retention. This study highlights the utilization of layered nanosheet arrays of niobates to achieve superior K-storage for KICs, paving the way towards the development of high-performance anodes for post lithium-ion batteries. © 2020
|
|
| 6. |
- Zhang, Leiting, et al.
(författare)
-
Unraveling gas evolution in sodium batteries by online electrochemical mass spectrometry
- 2021
-
Ingår i: Energy Storage Materials. - : Elsevier. - 2405-8289 .- 2405-8297. ; 42, s. 12-21
-
Tidskriftsartikel (refereegranskat)abstract
- Identification of gaseous decomposition products from irreversible side-reactions enables understanding of inner working of rechargeable batteries. Unlike for Li-ion batteries, the knowledge of the gas-evolution processes in Na-ion batteries is limited. Therefore, in this study, we have performed online electrochemical mass spectrometry to understand gassing behavior of model electrodes and electrolytes in Na-ion cells. Our results show that a less stable solid-electrolyte interphase (SEI) layer is developed in Na-ion cells as compared with that in Li-ion cells, which is mainly caused by higher solubility of SEI constituents in Na-electrolytes. Electrolyte reduction on the anode has much larger contribution to the gassing in the Na-ion cells, as gas evolution comes not only from direct electrolyte reduction but also from the soluble species, which migrate to the cathode and are decomposed there. During cell cycling, linear carbonates do not form an SEI layer on the anode, resulting in continuous electrolyte reduction, similar to Li-ion system but with much higher severity, while cyclic carbonates form a more stable SEI, preventing further decomposition of the electrolyte. Besides the standard electrolyte solvents, we have also assessed effects of several common electrolyte additives in their ability to stabilize the interphases. The results of this study provide understanding and guidelines for developing more durable electrode-electrolyte interphase, enabling higher specific energy and improved cycling stability for Na-ion batteries.
|
|
| 7. |
- Zhang, Miao, et al.
(författare)
-
From wood to thin porous carbon membrane : Ancient materials for modern ultrafast electrochemical capacitors in alternating current line filtering
- 2021
-
Ingår i: Energy Storage Materials. - : Elsevier BV. - 2405-8289 .- 2405-8297. ; 35, s. 327-333
-
Tidskriftsartikel (refereegranskat)abstract
- Ultrafast electrochemical capacitors with alternating current line filtering function have attracted growing attention owing to their potential to replace the state-of-the-art bulky aluminum electrolyte capacitors. In spite of rapid advance recently involving nanomaterials as electrode building units, it remains largely unexplored how to structurally and chemically engineer electrodes out of renewable resource with competitive or better rate performance. Herein, wood as a renewable resource was used to fabricate highly conductive, robust, porous thin carbon membranes as free-standing electrodes for ultrafast electrochemical capacitors. Transformation of wood slice to carbon membrane proceeds via wet-chemical treatment of wood slices and subsequent morphology maintaining carbonization by spark plasma sintering. Judiciously combining high conductivity, characteristic porous architecture with low tortuosity and high continuity, and the ultrathin thickness down to 20 ism, the carbon membrane-based electrochemical capacitor exhibits excellent frequency response with efficient 120 Hz filtering (phase angle = - 83.5 degrees). Compared to the latest electrodes for line filtering application that are fabricated from carbon nanotubes, graphene, and MXene, the wood-derived carbon membranes possess a competitive specific areal capacitance of up to 509.7 mu F cm(-2), and extremely low resistance-capacitance constant of 164.7 mu s, plus the inexpensive scalable fabrication strategy.
|
|
| 8. |
- Zhao, Yun, et al.
(författare)
-
Rational design of functional binder systems for high-energy lithium-based rechargeable batteries
- 2021
-
Ingår i: Energy Storage Materials. - : Elsevier. - 2405-8289 .- 2405-8297. ; 35, s. 353-377
-
Tidskriftsartikel (refereegranskat)abstract
- Binders, which maintain the structural integrity of electrodes, are critical components of lithium-based rechargeable batteries (LBRBs) that significantly affect battery performances, despite accounting for 2 to 5 wt% (up to 5 wt% but usually 2 wt%) of the entire electrode. Traditional polyvinylidene fluoride (PVDF) binders that interact with electrode components via weak van der Waals forces are effective in conventional LBRB systems (graphite/LiCoO2, etc.). However, its stable fluorinated structures limit the potential for further functionalization and inhibit strong interactions towards external substances. Consequently, they are unsuitable for next-generation battery systems with high energy density. There is thus a need for new functional binders with facile features compatible with novel electrode materials and chemistries. Here in this review we consider the strategies for rationally designing these functional binders. On the basis of fundamental understandings of the issues for high-energy electrode materials, we have summarized seven desired functions that binders should possess depending on the target electrodes where the binders will be applied. Then a variety of leading-edge functional binders are reviewed to show how their chemical structures realize these above functions and how the employment of these binders affects the cell's electrochemical performances. Finally the corresponding design strategies are therefore proposed, and future research opportunities as well as challenges relating to LBRB binders are outlined.
|
|
| 9. |
- Zheng, Wei, et al.
(författare)
-
MXene-manganese oxides aqueous asymmetric supercapacitors with high mass loadings, high cell voltages and slow self-discharge
- 2021
-
Ingår i: Energy Storage Materials. - : Elsevier. - 2405-8289 .- 2405-8297. ; 38, s. 438-446
-
Tidskriftsartikel (refereegranskat)abstract
- How to achieve high mass loadings while maintaining high energy and power densities together with slow self-discharge rates for aqueous asymmetric supercapacitors (AASCs) remains a great challenge. Herein, we tested an AASC using Ti3C2Tz MXene as the negative electrode, a mixture of manganese oxides, Mn3O4 and MnOOH, as the positive electrode with a saturated lithium chloride (14 M LiCl) electrolyte. This device, with electrode thicknesses of > 100 mu m, and a mass loading of similar to 10 mg cm(-2), resulted in an energy density of approximate to 30 Wh kg(-1) at 0.5 A g(-1), a power density of approximate to 23 kW kg(-1) at 20 A g(-1), an open cell voltage of 2.3 V, excellent rate capability and cycling stability. When allowed to self-discharge for 54 h at room temperature, similar to 66% of the voltage was retained. Crucially, after that time the cell voltage was > 1.5 V. This work opens a new opportunity for high performance, environmentally friendly AASCs, where high energy and power densities are combined with slow self-discharge rates at commercial mass loadings.
|
|
| 10. |
- Barros Neves de Araújo, Rafael, 1985, et al.
(författare)
-
Towards novel calcium battery electrolytes by efficient computational screening
- 2021
-
Ingår i: Energy Storage Materials. - : Elsevier BV. - 2405-8297. ; 39, s. 89-95
-
Tidskriftsartikel (refereegranskat)abstract
- The development of Ca conducting electrolytes is key to enable functional rechargeable Ca batteries. The here presented screening strategy is initially based on a combined density functional theory (DFT) and conductor-like screening model for real solvents (COSMO-RS) approach, which allows for a rational selection of electrolyte solvent based on a set of physico-chemical and electrochemical properties: solvation power, electrochemical stability window, viscosity, and flash and boiling points. Starting from 81 solvents, N,N-dimethylformamide (DMF) was chosen as solvent for further studies of cation-solvent interactions and subsequent comparisons vs. cation-anion interactions possibly present in electrolytes, based on a limited set of Ca-salts. A Ca first solvation shell of [Ca(DMF) ] was found to be energetically preferred, even as compared to ion-pairs and aggregates, especially for PF and TFSI as the anions. Overall, this points to Ca(TFSI) and Ca(PF ) dissolved in DMF to be a promising base electrolyte for Ca batteries from a physico-chemical point-of-view. While electrochemical assessments certainly are needed to verify this promise, the screening strategy presented is efficient and a useful stepping-stone to reduce the overall R&D effort.
|
|
