| 1. |
- Sun, Jinhua, 1987, et al.
(författare)
-
Critical Role of Functional Groups Containing N, S, and O on Graphene Surface for Stable and Fast Charging Li-S Batteries
- 2021
-
Ingår i: Small. - : Wiley. - 1613-6810 .- 1613-6829. ; 17:17
-
Tidskriftsartikel (refereegranskat)abstract
- Lithium‐sulfur (Li‐S) batteries are considered one of the most promising energy storage technologies, possibly replacing the state‐of‐the‐art lithium‐ion (Li‐ion) batteries owing to their high energy density, low cost, and eco‐compatibility. However, the migration of high‐order lithium polysulfides (LiPs) to the lithium surface and the sluggish electrochemical kinetics pose challenges to their commercialization. The interactions between the cathode and LiPs can be enhanced by the doping of the carbon host with heteroatoms, however with relatively low doping content (<10%) in the bulk of the carbon, which can hardly interact with LiPs at the host surface. In this study, the grafting of versatile functional groups with designable properties (e.g., catalytic effects) directly on the surface of the carbon host is proposed to enhance interactions with LiPs. As model systems, benzene groups containing N/O and S/O atoms are vertically grafted and uniformly distributed on the surface of expanded reduced graphene oxide, fostering a stable interface between the cathode and LiPs. The combination of experiments and density functional theory calculations demonstrate improvements in chemical interactions between graphene and LiPs, with an enhancement in the electrochemical kinetics, power, and energy densities.
|
|
| 2. |
- Grieco, Rebecca, et al.
(författare)
-
A significantly improved polymer||Ni(OH) 2 alkaline rechargeable battery using anthraquinone-based conjugated microporous polymer anode
- 2022
-
Ingår i: Materials Today Energy. - : Elsevier BV. - 2468-6069. ; 27
-
Tidskriftsartikel (refereegranskat)abstract
- Alkaline rechargeable batteries (ARBs) are predicted to be an attractive solution for large-scale electrochemical energy storage applications. However, their advancement is greatly hindered by the lack of high-performance and sustainable anode that can stably operate in less-corroding, low electrolyte concentration. Herein, we report the first example of polymer ARB able to operate in low concentrate electrolyte (1м potassium hydroxide [KOH]) due to the employment of a robust anthraquinone-based conjugated microporous polymer (IEP-11) as anode. The assembled IEP-11||Ni(OH)2 achieves high cell voltage (0.98 V), high gravimetric/areal capacities (150 mAh/g/7.2 mAh/cm2 at 3.5 and 65 mg/cm2, respectively), long cycle life (22,730 cycles, 960 h, 75% capacity retention at 20C), excellent rate performance (75 mAh/g at 50C) and low temperature operativity (75 mAh/g at −10 °C). Furthermore, rate capability, low-temperature performance and ability to prepare high mass loading anodes, along with low self-discharge is improved compared to conventional linear poly (anthraquinone sulfide) (PAQS) in commonly used 10 м KOH. This overall performance for IEP-11||Ni(OH)2 is not only far superior to that of PAQS||Ni(OH)2 owing to porous polymer's high specific surface area, combined micro-/mesoporosity and robust and mechanically stable three-dimensional (3D) architecture compared to the linear PAQS, but also surpass most of the reported organic||nickel [Ni]/cobalt [Co]/manganese [Mn] alkaline rechargeable batteries (ARBs).
|
|
| 3. |
- Sanchez Sanchez, Jaime, 1990, et al.
(författare)
-
All-Electrochemical Nanofabrication of Stacked Ternary Metal Sulfide/Graphene Electrodes for High-Performance Alkaline Batteries
- 2022
-
Ingår i: Small. - : Wiley. - 1613-6810 .- 1613-6829. ; 18
-
Tidskriftsartikel (refereegranskat)abstract
- Energy-storage materials can be assembled directly on the electrodes of a battery using electrochemical methods, this allowing sequential deposition, high structural control, and low cost. Here, a two-step approach combining electrophoretic deposition (EPD) and cathodic electrodeposition (CED) is demonstrated to fabricate multilayer hierarchical electrodes of reduced graphene oxide (rGO) and mixed transition metal sulfides (NiCoMnSx). The process is performed directly on conductive electrodes applying a small electric bias to electro-deposit rGO and NiCoMnSx in alternated cycles, yielding an ideal porous network and a continuous path for transport of ions and electrons. A fully rechargeable alkaline battery (RAB) assembled with such electrodes gives maximum energy density of 97.2 Wh kg−1 and maximum power density of 3.1 kW kg−1, calculated on the total mass of active materials, and outstanding cycling stability (retention 72% after 7000 charge/discharge cycles at 10 A g−1). When the total electrode mass of the cell is considered, the authors achieve an unprecedented gravimetric energy density of 68.5 Wh kg−1, sevenfold higher than that of typical commercial supercapacitors, higher than that of Ni/Cd or lead–acid Batteries and similar to Ni–MH Batteries. The approach can be used to assemble multilayer composite structures on arbitrary electrode shapes.
|
|
| 4. |
- Sanchez Sanchez, Jaime, 1990, et al.
(författare)
-
Electrophoretic coating of LiFePO4/Graphene oxide on carbon fibers as cathode electrodes for structural lithium ion batteries
- 2021
-
Ingår i: Composites Science and Technology. - : Elsevier BV. - 0266-3538. ; 208
-
Tidskriftsartikel (refereegranskat)abstract
- Carbon fibers (CF), commonly used in the structure of airplanes or cars, can also work as conductive electrodes in “structural batteries” for distributed energy storage. To this aim CF should be chemically functionalized, which is challenging due to their complex geometry and surface. Here, we describe an “all-electrostatic” approach taking advantage of the intrinsic conductivity of CF to coat them with a cathode material composed of LiFePO4 blended with nanosheets of electrochemically exfoliated graphene oxide (EGO). We first achieve electrostatic selfassembly of the nanometric components at the nanoscale, then use Electrophoretic Deposition (EPD) to obtain a uniform, macroscale coating on the fibers. We achieve a LiFePO4 loading >90 wt% featuring good adhesion on the carbon fibers, low degradation upon battery cycling, low charge transfer resistance. The electrode composite outperforms similar state-of-the-art cathode materials when used in Half-Cell vs. Li. Full battery cells using coated CF as cathode and pristine CF as anode yield specific energy density of 222.14 Wh⋅kg? 1 and power density of 0.29 kW⋅kg? 1 with 88.1% capacity retention at 1 C over 300 cycles, compatible with industrial applications of this technique in composites production.
|
|
| 5. |
- Xia, Zhenyuan, 1983, et al.
(författare)
-
Green synthesis of positive electrodes for high performance structural batteries - A study on graphene additives
- 2024
-
Ingår i: Composites Science and Technology. - 0266-3538. ; 251
-
Tidskriftsartikel (refereegranskat)abstract
- Carbon fibres (CF) have the potential to serve as versatile and multifunctional conductive electrodes within the concept of “structural batteries”. These batteries possess the unique ability to both store electrical energy and bear mechanical loads without requiring extra current collectors. However, numerous challenges remain on the path to commercializing structural batteries. One significant challenge lies in the fabrication process of CF-based cathode composites, including the poor adhesion of active materials to the CF surface and the use of hazardous organic solvents, such as N-methyl pyrrolidone (NMP) through traditional blade coating. In this study, we present a sustainable fabrication approach, using electrophoretic deposition (EPD) to construct positive electrode composites with lithium iron phosphate (LiFePO4) and graphene nanosheets. Especially, ethanol was used as a green solvent replacing NMP to minimize the environmental impact. Meanwhile, the influence of different types of graphene additives (three kinds of graphene nanoplatelets (GNP), four kinds of reduced graphene oxide (rGO) and one home-made graphene) to the relative battery performance were evaluated under a systematic comparative analysis. Among the tested graphene additives, LFP/rGO2 based positive electrode exhibits a desirable specific capacity of 126.2 mAhg−1, maintaining over 93% retention even under the demanding conditions of 2C over 500 cycles.
|
|
| 6. |
- Xia, Zhenyuan, 1983, et al.
(författare)
-
Selective deposition of metal oxide nanoflakes on graphene electrodes to obtain high-performance asymmetric micro-supercapacitors
- 2021
-
Ingår i: Nanoscale. - 2040-3372 .- 2040-3364. ; 13:5, s. 3285-3294
-
Tidskriftsartikel (refereegranskat)abstract
- To meet the charging market demands of portable microelectronics, there has been a growing interest in high performance and low-cost microscale energy storage devices with excellent flexibility and cycling durability. Herein, interdigitated all-solid-state flexible asymmetric micro-supercapacitors (A-MSCs) were fabricated by a facile pulse current deposition (PCD) approach. Mesoporous Fe2O3 and MnO2 nanoflakes were functionally coated by electrodeposition on inkjet-printed graphene patterns as negative and positive electrodes, respectively. Our PCD approach shows significantly improved adhesion of nanostructured metal oxide with crack-free and homogeneous features, as compared with other reported electrodeposition approaches. The as-fabricated Fe2O3/MnO2 A-MSCs deliver a high volumetric capacitance of 110.6 F cm(-3) at 5 mu A cm(-2) with a broad operation potential range of 1.6 V in neutral LiCl/PVA solid electrolyte. Furthermore, our A-MSC devices show a long cycle life with a high capacitance retention of 95.7% after 10 000 cycles at 100 mu A cm(-2). Considering its low cost and potential scalability to industrial levels, our PCD technique could be an efficient approach for the fabrication of high-performance MSC devices in the future.
|
|
| 7. |
- Xu, Johanna, 1989, et al.
(författare)
-
COATING OF LFP/GRAPHENE OXIDE ON CARBON FIBRES AS POSITIVE ELECTRODES FOR STRUCTURAL BATTERIES
- 2022
-
Ingår i: ECCM 2022 - Proceedings of the 20th European Conference on Composite Materials: Composites Meet Sustainability. ; 5, s. 240-245
-
Konferensbidrag (refereegranskat)abstract
- Structural battery composites are carbon fibre-based materials with the ability to simultaneously carry mechanical load and store electrical energy. This study investigates a method for manufacturing structural positive electrodes via electrophoretic deposition (EPD). Electrostatic forces on different scales are exploited in the EPD process. On the nanoscale, electrostatic interactions are employed for self-assembly of the nanometric components, followed by EPD on the macroscale with carbon fibres immersed in organic solution to attract the nanoscale components. Hereby, we use LiFePO4 as the active material, where electrochemically exfoliated graphene oxide (EGO) is compared with reduced graphene oxide (rGO) as a multifunctional carbon additive.
|
|
