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Blomquist, N., Koppolu, R., Dahlström, C., Toivakka, M. & Olin, H. (2020). Influence of Substrate in Roll-to-roll Coated Nanographite Electrodes for Metal-free Supercapacitors. Scientific Reports, 10(1), Article ID 5282.
Open this publication in new window or tab >>Influence of Substrate in Roll-to-roll Coated Nanographite Electrodes for Metal-free Supercapacitors
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2020 (English)In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 10, no 1, article id 5282Article in journal (Refereed) Published
Abstract [en]

Due to the high electric conductivity and large surface area of nanographites, such as graphene and graphite nanoplatlets, these materials have gained a large interest for use in energy storage devices. However, due to the thin flake geometry, the viscosity of aqueous suspensions containing these materials is high even at low solids contents. This together with the use of high viscosity bio-based binders makes it challenging to coat in a roll-to-roll process with sufficient coating thickness. Electrode materials for commercial energy storage devices are often suspended by organic solvents at high solids contents and coated onto metal foils used as current-collectors. Another interesting approach is to coat the electrode onto the separator, to enable large-scale production of flat cell stacks. Here, we demonstrate an alternative, water-based approach that utilize slot-die coating to coat aqueous nanographite suspension with nanocellulose binder onto the paper separator, and onto the current collector as reference, in aqueous metal-free supercapacitors. The results show that the difference in device equivalent series resistance (ESR) due to interfacial resistance between electrode and current collector was much lower than expected and thus similar or lower compared to other studies with a aqueous supercapacitors. This indicates that electrode coated paper separator substrates could be a promising approach and a possible route for manufacturing of low-cost, environmentally friendly and metal-free energy storage devices. 

National Category
Materials Chemistry
Identifiers
urn:nbn:se:miun:diva-38768 (URN)10.1038/s41598-020-62316-0 (DOI)2-s2.0-85082184284 (Scopus ID)
Available from: 2020-04-01 Created: 2020-04-01 Last updated: 2020-04-01
Rastabi, S. A., Mamoory, R. S., Blomquist, N., Phadatare, M. R. & Olin, H. (2020). Synthesis of a NiMoO4/3D-rGO nanocomposite via starch medium precipitation method for supercapacitor performance. Batteries, 6(1), Article ID 5.
Open this publication in new window or tab >>Synthesis of a NiMoO4/3D-rGO nanocomposite via starch medium precipitation method for supercapacitor performance
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2020 (English)In: Batteries, ISSN 2313-0105, Vol. 6, no 1, article id 5Article in journal (Refereed) Published
Abstract [en]

This paper presents research on the synergistic effects of nickel molybdate and reduced graphene oxide as a nanocomposite for further development of energy storage systems. An enhancement in the electrochemical performance of supercapacitor electrodes occurs by synthesizing highly porous structures and achieving more surface area. In this work, a chemical precipitation technique was used to synthesize the NiMoO4/3D-rGO nanocomposite in a starch media. Starch was used to develop the porosities of the nanostructure. A temperature of 350◦C was applied to transform graphene oxide sheets to reduced graphene oxide and remove the starch to obtain the NiMoO4/3D-rGO nanocomposite with porous structure. The X-ray diffraction pattern of the NiMoO4 nano particles indicated a monoclinic structure. Also, the scanning electron microscope observation showed that the NiMoO4 NPs were dispersed across the rGO sheets. The electrochemical results of the NiMoO4/3D-rGO electrode revealed that the incorporation of rGO sheets with NiMoO4 NPs increased the capacity of the nanocomposite. Therefore, a significant increase in the specific capacity of the electrode was observed with the NiMoO4/3D-rGO nanocomposite (450 Cg−1 or 900 Fg−1) when compared with bare NiMoO4 nanoparticles (350 Cg−1 or 700 Fg−1) at the current density of 1 A g−1. Our findings show that the incorporation of rGO and NiMoO4 NP redox reactions with a porous structure can benefit the future development of supercapacitors. 

Keywords
Electrochemical performance, NiMoO4 NPs, NiMoO4/3D-rGO nanocomposite, Porous structure, Starch
National Category
Chemical Sciences
Identifiers
urn:nbn:se:miun:diva-38353 (URN)10.3390/batteries6010005 (DOI)000523703600004 ()2-s2.0-85078484614 (Scopus ID)
Available from: 2020-02-03 Created: 2020-02-03 Last updated: 2020-04-23Bibliographically approved
Blomquist, N., Alimadadi, M., Hummelgård, M., Dahlström, C., Olsen, M. & Olin, H. (2019). Effects of Geometry on Large-scale Tube-shear Exfoliation of Multilayer Graphene and Nanographite in Water. Scientific Reports, 9(1), Article ID 8966.
Open this publication in new window or tab >>Effects of Geometry on Large-scale Tube-shear Exfoliation of Multilayer Graphene and Nanographite in Water
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2019 (English)In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 9, no 1, article id 8966Article in journal (Refereed) Published
Abstract [en]

Industrially scalable methods for the production of graphene and other nanographites are needed to achieve cost-efficient commercial products. At present, there are several available routes for the production of these materials but few allow large-scale manufacturing and environmentally friendly low-cost solvents are rarely used. We have previously demonstrated a scalable and low-cost industrial route to produce nanographites by tube-shearing in water suspensions. However, for a deeper understanding of the exfoliation mechanism, how and where the actual exfoliation occurs must be known. This study investigates the effect of shear zone geometry, straight and helical coil tubes, on this system based on both numerical simulation and experimental data. The results show that the helical coil tube achieves a more efficient exfoliation with smaller and thinner flakes than the straight version. Furthermore, only the local wall shear stress in the turbulent flow is sufficient for exfoliation since the laminar flow contribution is well below the needed range, indicating that exfoliation occurs at the tube walls. This explains the exfoliation mechanism of water-based tube-shear exfoliation, which is needed to achieve scaling to industrial levels of few-layer graphene with known and consequent quality.

National Category
Natural Sciences
Identifiers
urn:nbn:se:miun:diva-36084 (URN)10.1038/s41598-019-45133-y (DOI)000472137700062 ()2-s2.0-85067662886 (Scopus ID)
Available from: 2019-05-06 Created: 2019-05-06 Last updated: 2019-10-16Bibliographically approved
Blomquist, N. (2019). Large-Scale Graphene Production for Environmentally Friendly and Low-Cost Energy Storage: Production, Coating, and Applications. (Doctoral dissertation). Sundsvall: Mid Sweden University
Open this publication in new window or tab >>Large-Scale Graphene Production for Environmentally Friendly and Low-Cost Energy Storage: Production, Coating, and Applications
2019 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

There is great demand for energy-efficient, environmentally sustainable, and cost-effective electrical energy storage devices. One important aspect of this demand is the need for automotive electrification to achieve more energy-efficient transportation at a reasonable cost, thus supporting a fossil-fuel free society. Another important aspect is the requirement for energy storage in the growing field of renewable energy production from wind and solar sources, which generates an irregular supply of electricity due to weather conditions.Much of the research in this area has been conducted in the field of battery technology with impressive results, but the need for rapid storage devices such as supercapacitors is growing. Due to the excellent ability of supercapacitors to handle short peak power pulses with high efficiency along with their long lifetime and superior cyclability, their implementations range from small consumer electronics to electric vehicles and stationary grid applications. Supercapacitors also have the potential to complement batteries to improve pulse efficiency and lifetime of the system, however, the cost of supercapacitors is a significant issue for large-scale commercial use, leading to a demand for sustainable, low-cost materials and simplified manufacturing processes. An important way to address this need is to develop a cost-efficient and environment-friendly large-scale process to produce highly conductive nanographites, such as graphene and graphite nanoplatelets, along with methods to manufacture low-cost electrodes from large area coating.

In this thesis, I present a novel process to mechanically exfoliate industrial quantities of nanographite from graphite in an aqueous environment with low energy consumption and at controlled shear conditions. The process is based on hydrodynamic tube-shearing and can produce both multilayer graphene and nanometer-thick and micrometer-wide flakes of nanographite. I also describe the production of highly conductive and robust carbon composites based on the addition of nanocellulose during production; these are suitable as electrodes in applications ranging from supercapacitors and batteries to printed electronics and solar cells.Furthermore I demonstrate a scalable route for roll-to-roll coating of the nanographite-nanocellulose electrode material and propose a novel aqueous, low-cost, and metal-free supercapacitor concept with graphite foil functioning as the current collector. The supercapacitors possessedmore than half the specific capacitance of commercial units but achieved a material cost reduction of more than 90 %, demonstrating anenvironment-friendly, low-cost alternative to conventional supercapacitors.

Abstract [sv]

Det finns en stor efterfrågan av energieffektiva, miljömässigt hållbara och kostnadseffektiva elektriska energilagringsenheter. En viktig del av denna efterfrågan kommer från fordonsindustrins behov av elektrifiering, för att uppnå mer energieffektiva fordon till en rimlig kostnad och på så vis bidra till ett fossilfritt samhälle. En annan viktig del är behovet av energilagring för den ökande andelen förnybar energiproduktion från sol- och vindkraft, som genererar elektrisk energi oregelbundet utifrån gällande väderförhållanden. Det pågår mycket forskning inom området för batteriteknik och framgångarna är imponerande men behovet växer också snabbt för snabba energilagrare som exempelvis superkondensatorer. Tack vare superkondensatorernas utmärkta prestanda, när det gäller att hantera korta effektpulser med hög effektivitet tillsammans med dess långa livslängd och överlägsna cyklingsbarhet, sträcker sig applikationerna frånhemelektronik till elfordon och elnätsapplikationer. Superkondensatorer har också potential att komplettera batterier för att uppnå energilagringssystem med ökad pulseffiktivitet och livslängd. Nackdelen är superkondensatorns kostnad, som markant hämmar storskaligkommersialisering, och således kräver utveckling av hållbara och kostnadseffektiva material tillsammans med förenklade tillverkningsmetoder. Ett sätt att lösa detta på, är att utveckla en kostnadseffektiv och miljövänlig process i stor skala för att framställa nanografit med hög elektrisk ledningsförmåga, så som grafén och grafitnanoflak.

I denna avhandling presenterar jag en ny process för att mekaniskt exfoliera grafit till nanografit storskaligt i vattendispersion, med en låg energiåtgång och under kontrollerade skjuvförhållanden. Processen är baserad på hydrodynamisk skjuvning i rör och denproducerar grafen samt nanometertunna och mikrometerbreda flak av nanografit. Som tillägg visar jag också hur robusta kompositer kan tillverkas med hög ledningsförmåga genom att tillsätta nanofibrillerad cellulosa under processen. Dessa kompositer är lämpliga som elektroder i applikationer från superkondensatorer och batterier till tryckt elektronik och solceller.Jag demonstrerar också en skalbar metod för rulle-till-rulle bestrykning av nanografit-nanocellulosa-materialet samt föreslår ett nytt lågkostnads-koncept för metall-fria superkondensatorer med vattenbaserad elektrolyt, där vi använt grafitfolie som kontakt. Superkondensatorerna hade mer än halva den specifika kapacitansen jämfört med kommersiella enheter men materialkostnaden var 90 % lägre, vilket visar på ett miljövänligt lågkostnadsalternativ till konventionella superkondensatorer.

Place, publisher, year, edition, pages
Sundsvall: Mid Sweden University, 2019. p. 90
Series
Mid Sweden University doctoral thesis, ISSN 1652-893X ; 297
Keywords
Graphene, Energy storage, Supercapacitors, EDLC
National Category
Other Physics Topics
Identifiers
urn:nbn:se:miun:diva-36068 (URN)978-91-88527-99-8 (ISBN)
Public defence
2019-05-10, O102, Holmgatan 10, Sundsvall, 10:15 (English)
Opponent
Supervisors
Note

Vid tidpunkten för disputationen var följande delarbeten opublicerade: delarbete 3 (inskickat), delarbete 5 (manuskript).

At the time of the doctoral defence the following papers were unpublished: paper 3 (submitted), paper 5 (manuscript).

Available from: 2019-05-06 Created: 2019-05-02 Last updated: 2019-05-06Bibliographically approved
Zhang, R., Hummelgård, M., Örtegren, J., Yang, Y., Andersson, H., Balliu, E., . . . Olin, H. (2019). Sensing body motions based on charges generated on the body. Nano Energy, 63, Article ID 103842.
Open this publication in new window or tab >>Sensing body motions based on charges generated on the body
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2019 (English)In: Nano Energy, ISSN 2211-2855, E-ISSN 2211-3282, Vol. 63, article id 103842Article in journal (Refereed) Published
Abstract [en]

The sensing of body motions is of great importance in areas such as healthcare, rehabilitation, and human-computer interactions. Different methods have been developed based on visual or electrical signals. However, such signals are acquired by external devices and are not intrinsic signals that are created on the body. Here, we report a new universal body motion sensor (UBS) to detect motions based on the intrinsic contact electrification (CE) of the skin or electrical induction (EI) of the body. The CE or EI generates charges on the body, leading to potential differences between the body and ground that can be measured to identify different body motions, such as motions of the head, arms, fingers, waist, legs, feet and toes. Proof-of-concept experiments have demonstrated that the UBS can be used to monitor the conditions of people with Parkinson's disease (PD) and to quantitatively monitor the recovery of those with a leg injury, suggesting great potential for healthcare applications.

Keywords
Body motions, Sensors, Charges, Contact electrification, Electrical induction, Healthcare
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:miun:diva-36826 (URN)10.1016/j.nanoen.2019.06.038 (DOI)000480422400034 ()2-s2.0-85068234493 (Scopus ID)
Available from: 2019-08-12 Created: 2019-08-12 Last updated: 2019-10-16Bibliographically approved
Phadatare, M. R., Patil, R., Blomquist, N., Forsberg, S., Örtegren, J., Hummelgård, M., . . . Olin, H. (2019). Silicon-Nanographite Aerogel-Based Anodes for High Performance Lithium Ion Batteries. Scientific Reports, 9, Article ID 14621.
Open this publication in new window or tab >>Silicon-Nanographite Aerogel-Based Anodes for High Performance Lithium Ion Batteries
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2019 (English)In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 9, article id 14621Article in journal (Refereed) Published
Abstract [en]

To increase the energy storage density of lithium-ion batteries, silicon anodes have been explored due to their high capacity. One of the main challenges for silicon anodes are large volume variations during the lithiation processes. Recently, several high-performance schemes have been demonstrated with increased life cycles utilizing nanomaterials such as nanoparticles, nanowires, and thin films. However, a method that allows the large-scale production of silicon anodes remains to be demonstrated. Herein, we address this question by suggesting new scalable nanomaterial-based anodes. Si nanoparticles were grown on nanographite flakes by aerogel fabrication route from Si powder and nanographite mixture using polyvinyl alcohol (PVA). This silicon-nanographite aerogel electrode has stable specific capacity even at high current rates and exhibit good cyclic stability. The specific capacity is 455 mAh g−1 for 200th cycles with a coulombic efficiency of 97% at a current density 100 mA g−1.

Keywords
Silicon-Nanographite Aerogel-Based Anodes for High Performance Lithium Ion Batteries Supplementary Information
National Category
Nano Technology
Identifiers
urn:nbn:se:miun:diva-37569 (URN)10.1038/s41598-019-51087-y (DOI)000489555900015 ()2-s2.0-85073112106 (Scopus ID)
Available from: 2019-10-24 Created: 2019-10-24 Last updated: 2019-11-14Bibliographically approved
Rastabi, S. A., Mamoory, R. S., Dabir, F., Blomquist, N., Phadatare, M. R. & Olin, H. (2019). Synthesis of NiMoO4/3D-rGO Nanocomposite in Alkaline Environments for Supercapacitor Electrodes. Crystals, 9(1), Article ID 31.
Open this publication in new window or tab >>Synthesis of NiMoO4/3D-rGO Nanocomposite in Alkaline Environments for Supercapacitor Electrodes
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2019 (English)In: Crystals, ISSN 2073-4352, Vol. 9, no 1, article id 31Article in journal (Refereed) Published
Abstract [en]

Although Graphene oxide (GO)-based materials is known as a favorable candidate for supercapacitors, its conductivity needs to be increased. Therefore, this study aimed to investigate the performance of GO-based supercapicitor with new methods. In this work, an ammonia solution has been used to remove the oxygen functional groups of GO. In addition, a facile precipitation method was performed to synthesis a NiMoO4/3D-rGO electrode with purpose of using synergistic effects of rGO conductivity properties as well as NiMoO4 pseudocapacitive behavior. The phase structure, chemical bands and morphology of the synthesized powders were investigated by X-ray diffraction (XRD), Raman spectroscopy, and field emission secondary electron microscopy (FE-SEM). The electrochemical results showed that the NiMoO4/3D-rGO(II) electrode, where ammonia has been used during the synthesis, has a capacitive performance of 932 Fg(-1). This is higher capacitance than NiMoO4/3D-rGO(I) without using ammonia. Furthermore, the NiMoO4/3D-rGO(II) electrode exhibited a power density of up to 17.5 kW kg(-1) and an energy density of 32.36 Wh kg(-1). These results showed that ammonia addition has increased the conductivity of rGO sheets, and thus it can be suggested as a new technique to improve the capacitance.

Keywords
renewable energy systems, pseudocapacitive behavior, electrochemical results, ammonia, oxygen groups
National Category
Chemical Engineering
Identifiers
urn:nbn:se:miun:diva-35806 (URN)10.3390/cryst9010031 (DOI)000458578100031 ()
Available from: 2019-03-19 Created: 2019-03-19 Last updated: 2019-03-19Bibliographically approved
Zhang, R., Hummelgård, M., Olin, H., Blomquist, N. & Andres, B. (2019). The application of papers in energy harvesting and storage. In: : . Paper presented at 2019 China International Specialty Papers Expo & Conference, Quzhou, China, October 16-18, 2019.
Open this publication in new window or tab >>The application of papers in energy harvesting and storage
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2019 (English)Conference paper, Oral presentation with published abstract (Refereed)
National Category
Physical Sciences
Identifiers
urn:nbn:se:miun:diva-37824 (URN)
Conference
2019 China International Specialty Papers Expo & Conference, Quzhou, China, October 16-18, 2019
Available from: 2019-11-28 Created: 2019-11-28 Last updated: 2019-12-13Bibliographically approved
Andres, B., Dahlström, C., Blomquist, N., Norgren, M. & Olin, H. (2018). Cellulose binders for electric double-layer capacitor electrodes: The influence of cellulose quality on electrical properties. Materials & design, 141, 342-349
Open this publication in new window or tab >>Cellulose binders for electric double-layer capacitor electrodes: The influence of cellulose quality on electrical properties
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2018 (English)In: Materials & design, ISSN 0264-1275, E-ISSN 1873-4197, Vol. 141, p. 342-349Article in journal (Refereed) Published
Abstract [en]

Cellulose derivatives are widely used as binders and dispersing agents in different applications. Binders composed of cellulose are an environmentally friendly alternative to oil-based polymer binding agents. Previously, we reported the use of cellulose nanofibers (CNFs) as binders in electrodes for electric double-layer capacitors (EDLCs). In addition to good mechanical stability, we demonstrated that CNFs enhanced the electrical performance of the electrodes. However, cellulose fibers can cover a broad range of length scales, and the quality requirements from an electrode perspective have not been thoroughly investigated. To evaluate the influence of fiber quality on electrode properties, we tested seven samples with different fiber dimensions that are based on the same kraft pulp. To capture the length scale from fibers to nanofibrils, we evaluated the performance of the untreated kraft pulp, refined fibers, microfibrillated cellulose (MFC) and CNFs. Electrodes with kraft pulp or refined fibers showed the lowest electrical resistivity. The specific capacitances of all EDLCs were surprisingly similar, but slightly lower for the EDLC with CNFs. The same electrode sample with CNFs also showed a slightly higher equivalent series resistance (ESR), compared to those of the other EDLCs. Graphite dispersions with MFC showed the best dispersion stability. 

Keywords
Cellulose, Electric double-layer capacitor, Graphite, Nanocellulose, Nanocomposite, Supercapacitor
National Category
Chemical Engineering
Identifiers
urn:nbn:se:miun:diva-32766 (URN)10.1016/j.matdes.2017.12.041 (DOI)000424945300031 ()2-s2.0-85040002856 (Scopus ID)
Available from: 2018-01-30 Created: 2018-01-30 Last updated: 2018-07-19Bibliographically approved
Blomquist, N., Wells, T., Andres, B., Bäckström, J., Forsberg, S. & Olin, H. (2017). Metal-free supercapacitor with aqueous electrolyte and low-cost carbon materials. Scientific Reports, 7, Article ID 39836.
Open this publication in new window or tab >>Metal-free supercapacitor with aqueous electrolyte and low-cost carbon materials
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2017 (English)In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 7, article id 39836Article in journal (Refereed) Published
Abstract [en]

Electric double-layer capacitors (EDLCs) or supercapacitors (SCs) are fast energy storage devices with high pulse efficiency and superior cyclability, which makes them useful in various applications including electronics, vehicles and grids. Aqueous SCs are considered to be more environmentally friendly than those based on organic electrolytes. Because of the corrosive nature of the aqueous environment, however, expensive electrochemically stable materials are needed for the current collectors and electrodes in aqueous SCs. This results in high costs for a given energy-storage capacity. To address this, we developed a novel low-cost aqueous SC using graphite foil as the current collector and a mix of graphene, nanographite, simple water-purification carbons and nanocellulose as electrodes. The electrodes were coated directly onto the graphite foil by using casting frames and the SCs were assembled in a pouch cell design. With this approach, we achieved a material cost reduction of greater than 90% while maintaining approximately one-half of the specific capacitance of a commercial unit, thus demonstrating that the proposed SC can be an environmentally friendly, low-cost alternative to conventional SCs.

Place, publisher, year, edition, pages
Nature Publishing Group, 2017
Keywords
Supercapacitor, EDLC, Graphene, Graphite, Nanoparticles
National Category
Composite Science and Engineering Condensed Matter Physics
Identifiers
urn:nbn:se:miun:diva-29827 (URN)10.1038/srep39836 (DOI)000391182900001 ()2-s2.0-85008701942 (Scopus ID)
Funder
Swedish Energy Agency
Note

Published online:05 January 2017

Available from: 2017-01-06 Created: 2017-01-06 Last updated: 2019-05-02Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-4303-2585

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