| 1. |
- Sun, Bing, et al.
(författare)
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Towards Solid-State 3D-Microbatteries using Functionalized Polycarbonate-based Polymer Electrolytes
- 2018
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Ingår i: ACS Applied Materials and Interfaces. - 1944-8244 .- 1944-8252. ; 10:3, s. 2407-2413
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Tidskriftsartikel (refereegranskat)abstract
- 3D-microbatteries (3D-MBs) impose new demands for theselection, fabrication and compatibility of the different battery components, notleast the electrolytes. Herein, solid polymer electrolytes (SPEs) based on poly(trimethylene carbonate) (PTMC) have been implemented in 3D-MB systems. 3D electrodes of two different architectures, LiFePO4-coated carbon foams and Cu2O-coated Cu nanopillars, have been coated with SPEs and used in Li-cells. Functionalized PTMC with hydroxyl end groups was found to enable uniform and well-covering coatings on LiFePO4-coated carbon foams, although the cell cycling performance was limited by the large SPE resistance. By employing a SPE prepared from a copolymer of TMC and caprolactone (CL), with higher ionic conductivity, Li-cells composed of Cu2O-coated Cu nanopillars were constructed and tested both at room temperature and 60 °C. The footprint areal capacity of the cells was ca. 0.02 mAh cm-2 for an area gain factor (AF) of 2.5, and 0.2 mAh cm-2 for a relatively dense nanopillar-array (AF=25) at a current density of 0.008 mA cm-2at ambient temperature (22±1 °C). These results provide new routes towards the realization of all-solid-state 3D-MBs.
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| 2. |
- Klein, Edina, et al.
(författare)
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Elucidating the development of cooperative anode-biofilm-structures
- 2024
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Ingår i: Biofilm. - : Elsevier. - 2590-2075. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- Microbial electrochemical systems are a highly versatile platform technology with a particular focus on the interplay of chemical and electrical energy conversion and offer immense potential for a sustainable bioeconomy. The industrial realization of this potential requires a critical focus on biofilm optimization if performance is to be controlled over a long period of time. Moreover, the aspect and influence of cooperativity has to be addressed as many applied anodic bioelectrochemical systems will most likely be operated with a diversity of interacting microbial species. Hence, the aim of this study was to analyze how interspecies dependence and cooperativity of a model community influence the development of anodic biofilms. To investigate biofilm activity in a spatially resolved manner, a microfluidic bioelectrochemical flow cell was developed that can be equipped with user-defined electrode materials and operates under laminar flow conditions. With this infrastructure, the development of single and co-culture biofilms of the two model organisms Shewanella oneidensis and Geobacter sulfurreducens on graphite electrodes was monitored by optical coherence tomography analysis. The interdependence in the co-culture biofilm was achieved by feeding the community with lactate, which is converted by S. oneidensis into acetate, which in turn serves as substrate for G. sulfurreducens. The results show that co-cultivation resulted in the formation of denser biofilms than in single culture. Moreover, we hypothesize that S. oneidensis in return utilizes the conductive biofilm matrix build by G. sulfurreducens for direct interspecies electron transfer (DIET) to the anode. FISH analysis revealed that the biofilms consisted of approximately two-thirds G. sulfurreducens cells, which most likely formed a conductive 3D network throughout the biofilm matrix, in which evenly distributed tubular S. oneidensis colonies were embedded without direct contact to the anode surface. Live/dead staining shows that the outermost biofilm contained almost exclusively dead cells (98 %), layers near the anode contained 45–56 % and the entire biofilm contained 82 % live cells. Our results exemplify how the architecture of the exoelectrogenic biofilm dynamically adapts to the respective process conditions.
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| 3. |
- Lindgren, Fredrik, et al.
(författare)
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Breaking Down a Complex System : Interpreting PES Peak Positions for Cycled Li-ion Battery Electrodes
- 2017
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Ingår i: The Journal of Physical Chemistry C. - : American Chemical Society (ACS). - 1932-7447 .- 1932-7455. ; 121, s. 27303-27312
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Tidskriftsartikel (refereegranskat)abstract
- Photoelectron spectroscopy (PES) is an important technique for tracing and understanding the side reactions responsible for decreasing performance of Li-ion batteries. Interpretation of different spectral components is dependent on correct binding energy referencing and for battery electrodes this is highly complex. In this work, we investigate the effect on binding energy reference points in PES in correlation to solid electrolyte interphase (SEI) formation, changing electrode potentials and state of charge variations in Li-ion battery electrodes. The results show that components in the SEI have a significantly different binding energy reference point relative to the bulk electrode material (i.e. up to 2 eV). It is also shown that electrode components with electronically insulating/semi-conducting nature are shifted as a function of electrode potential relative to highly conducting materials. Further, spectral changes due to lithiation are highly depending on the nature of the active material and its lithiation mechanism. Finally, a strategy for planning and evaluating PES experiments on battery electrodes is proposed where some materials require careful choice of one or more internal reference points while others may be treated essentially without internal calibration.
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| 4. |
- Lindgren, Fredrik, et al.
(författare)
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On the Capacity Losses Seen for Optimized Nano-Si Composite Electrodes in Li-Metal Half-Cells
- 2019
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Ingår i: Advanced Energy Materials. - : Wiley. - 1614-6832 .- 1614-6840. ; 9:33
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Tidskriftsartikel (refereegranskat)abstract
- While the use of silicon‐based electrodes can increase the capacity of Li‐ion batteries considerably, their application is associated with significant capacity losses. In this work, the influences of solid electrolyte interphase (SEI) formation, volume expansion, and lithium trapping are evaluated for two different electrochemical cycling schemes using lithium‐metal half‐cells containing silicon nanoparticle–based composite electrodes. Lithium trapping, caused by incomplete delithiation, is demonstrated to be the main reason for the capacity loss while SEI formation and dissolution affect the accumulated capacity loss due to a decreased coulombic efficiency. The capacity losses can be explained by the increasing lithium concentration in the electrode causing a decreasing lithiation potential and the lithiation cut‐off limit being reached faster. A lithium‐to‐silicon atomic ratio of 3.28 is found for a silicon electrode after 650 cycles using 1200 mAhg−1 capacity limited cycling. The results further show that the lithiation step is the capacity‐limiting step and that the capacity losses can be minimized by increasing the efficiency of the delithiation step via the inclusion of constant voltage delithiation steps. Lithium trapping due to incomplete delithiation consequently constitutes a very important capacity loss phenomenon for silicon composite electrodes.
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| 5. |
- Liu, Chenjuan, 1988-, et al.
(författare)
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Growth of NaO2 in Highly Efficient Na–O2 Batteries Revealed by Synchrotron In Operando X-ray Diffraction
- 2017
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Ingår i: ACS Energy Letters. - : American Chemical Society (ACS). - 2380-8195. ; 2, s. 2440-2444
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The development of Na–O2 batteries requires understanding the formation of reaction products, as different groups reported compounds such as sodium peroxide, sodium superoxide, and hydrated sodium peroxide as the main discharge products. In this study, we used in operando synchrotron radiation powder X-ray diffraction (SR-PXD) to (i) quantitatively track the formation of NaO2 in Na–O2 cells and (ii) measure how the growth of crystalline NaO2 is influenced by the choice of electrolyte salt. The results reveal that the discharge could be divided into two time regions and that the formation of NaO2 during the major part of the discharge reaction is highly efficient. The findings indicate that the cell with NaOTf salt exhibited higher capacity than the cell with NaPF6 salt, whereas the average domain size of NaO2 particles decreases during the discharge. This fundamental insight brings new information on the working mechanism of Na–O2 batteries.
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| 6. |
- Malinovskis, Paulius, et al.
(författare)
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Synthesis and characterization of multicomponent (CrNbTaTiW)C films for increased hardness and corrosion resistance
- 2018
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Ingår i: Materials & design. - : Elsevier BV. - 0264-1275 .- 1873-4197. ; 149, s. 51-62
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Tidskriftsartikel (refereegranskat)abstract
- Multicomponent carbide thin films of (CrNbTaTiW)C (30–40 at.% C) with different metal contents were depos-ited at different temperatures using non-reactive DC magnetron sputtering. The lattice distortion for the metallattice was estimated to vary from about 3 to 5%. Most films crystallized in the cubic B1 structure but Ta/W-rich films deposited at 600 °C exhibited a tetra gonal distortion. X-ray diffraction results sh ow that near-equimolar films exhibited a strong (111) texture. In contrast, Ta/W-rich films exhibited a shift from (111) to(100) texture at 450 °C. The in-plane relationship was determined to MC(111)[-12-1]//Al2O3(001)[110] with alattice mismatch of about 11% along the Al2O3[110] direction. A segregation of Cr to the grain boundaries was ob-served in all films. The microstructure was found to be the most important factor for high hardness. Less denseNb-rich and near-equimolar films deposited at low tem peratures exhib ited the low est hardnes s (12 GPa),while very dense Ta/W-rich high temperature films were found to be the hardest (36 GPa). No correlation wasfound between the lattice distortion and the hardness. Corrosion studies revealed that the multicomponentfilms exhibited excellent corrosion resistance, superior to that of a reference hyper-duplex stainless steel, in1.0 M HCl.
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| 7. |
- Rehnlund, David, 1986-, et al.
(författare)
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Dendrite-free lithium electrode cycling via controlled nucleation in low LiPF6 concentration electrolytes
- 2018
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Ingår i: Materials Today. - : Elsevier BV. - 1369-7021 .- 1873-4103. ; 21:10, s. 1010-1018
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Tidskriftsartikel (refereegranskat)abstract
- Lithium metal electrodes are not widely used in rechargeable batteries as dendritic lithium growth and electrolyte reactions raise serious stability and safety concerns. In this study, we show that reproducible two-dimensional lithium deposition can be realized using a lithium salt concentration of 0.020 M, an added supporting salt, and a short lithium nucleation pulse. This approach, which is common in electrodeposition of metals, increases the lithium nuclei density on the electrode surface and decreases the extent of Li+ migration favoring dendritic lithium growth. Contrary to common belief, ascribing the dendrite problem to heterogeneous lithium nucleation due to an unstable solid electrolyte interphase layer, we show that the main lithium deposition problem stems from the difficulty to obtain two-dimensional deposition at the low lithium deposition overpotentials encountered in conventional high-lithium concentration electrolytes. The present results hence clearly demonstrate that two-dimensional lithium deposition can be realized in lithium-metal-based batteries.
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| 8. |
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| 9. |
- Rehnlund, David, 1986-, et al.
(författare)
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Electrochemical Manufacturing and Characterisation of Nanostructured Electrodes for Lithium based Batteries
- 2018
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Due to their high energy and power densities, lithium-ion batteries are the primary choice for application in consumer electronics. Although new electrode materials for Li-ion batteries are developed continuously, relatively little attention has so far been paid to the use of electrochemical methods in the manufacturing of battery materials. In the field of microbatteries, electrodeposition has, nevertheless, become an important technique for the manufacturing of current collectors, electrode materials and electrolytes [1]. During the last few years it has also been shown that electrochemically nanostructured electrodes lacking binders and other additives can facilitate the attainment of an improved understanding of the electrochemical reactions taking place in lithium based batteries. This presentation will focus on the development of electrochemical approaches for the manufacturing and study of nanostructured electrode materials for lithium based batteries. It will be shown that electrodeposition can be used for the manufacturing of 3-D copper and aluminium [1] current collectors as well as the coating of these with thin layers of anode or cathode materials. Electrochemical manufacturing and characterisation of materials such as multilayered Cu/Cu2O nanorods [2], Sn/SnO2 particles [3] and TiO2 nanotubes (see Figure 1) will be discussed, as well as a new approach for the manufacturing of TiO2 nanotube size gradient based electrodes [4]. Some fundamental issues regarding the electrochemical processes in the electrochemically manufactured materials, including the formation of “cathodic passive layers” and “trapping of lithium” in current collectors and alloy forming electrode materials [5] and the electrodeposition of homogeneous lithium films on lithium electrodes (see Figure 1) will likewise be discussed. References [1] K. Edström, D. Brandell, T. Gustafsson, L. Nyholm, Electrodeposition as a tool for 3D Microbattery Fabrication, Electrochem. Soc. Interface, 20 (2011) 41.[2] D. Rehnlund, M. Valvo, C. –W. Tai, J. Ångström, M. Sahlberg, K. Edström, L. Nyholm, Electrochemical fabrication and characterization of Cu/Cu2O multi-layered micro and nanorods in Li-ion batteries, Nanoscale, 7 (2015) 13591.[3] S. Böhme, K. Edström, L. Nyholm, Overlapping and Rate Controlling Electrochemical Reactions for Tin(IV) Oxide Electrodes in Lithium-Ion Batteries, J. Electroanal. Chem., 797 (2017) 47.[4] W. Wei, F. Björefors, L. Nyholm, Hybrid energy storage devices based on monolithic electrodes containing well-defined TiO2 nanotube size gradients, Electrochim. Acta, 176 (2015) 1393.
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| 10. |
- Rehnlund, David, 1986-
(författare)
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Electrochemically nanostructured electrodes for Li-ion microbatteries
- 2013
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Electrodeposition is a promising technique for fabricating complex nanostructures and coating these with suitable thin films of active materials. The research presented in this thesis aims at the development of new electro- chemical methods for the synthesis of nanostructured electrodes suitable for Li-ion microbatteries. Electrodes based on nanostructured Cu and Al current collectors have been investigated to provide insight into the fabrication of both anodes and cathodes.Coating 3D aluminium current collectors with a vanadium oxide thin film is generally accompanied by aluminium corrosion due to the oxidative environment employed in the electrodeposition. To circumvent this issue a protective intermediate MnOx coating was implemented which suppresses the Al corrosion thereby facilitating subsequent vanadium oxide deposition.3D Cu electrodes with thin Cu2O coatings were fabricated to investigate their electrochemical properties and the mechanism of the Cu2O conversion reaction. Impressive high-rate cycling capabilities and capacity retention were observed with capacities corresponding to 130% of the theoretical capacity obtained after 390 cycles. This capacity gain was linked to electro- chemical milling of the Cu2O particles producing particles smaller than 5 nm. A distribution of particles with different sizes was also observed during the electrochemical analysis. This gave rise to a substantial redox potential distribution and a large electroactive potential window.
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| 11. |
- Rehnlund, David, 1986-
(författare)
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Insights into Electrochemical Energy Storage by use of Nanostructured Electrodes
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Template-assisted electrodeposition is a powerful technique for fabricating complex nanostructured electrodes. Through the use of pulsed-electrodeposition nanostructured electrodes of Al, Cu and Sn have been realised and subsequently coated electrochemically with V2O5, MnxO, Li, Cu2O and a polymer electrolyte. Nanorods with a multi-layered Cu2O/Cu structure have likewise been produced through electrodeposition. Nanostructured electrodes are ideal for studying electrochemical energy storage and have as such been used to investigate the electrochemistry of conversion and alloying reactions in detail.Key properties of the Cu2O conversion reaction were found to be dependent on the particle size. Prolonged cycling was seen to induce an electrochemical milling process which reduced the particle size. This process was found to improve the cell capacity retention due to improved accessibility of the material. The redox potential at which the particles react was found to be size dependent as smaller particles reacted at lower potentials.The Li-alloying reaction was also investigated by analysing several different alloy-forming materials. All materials exhibited a decline in capacity during cell cycling. This decline was observed to be time dependent and could as such be explained by a diffusion limited process. Moreover, the capacity losses were found to occur during partial lithiation of the electrode material leading to Li trapping in the electrode material. Li trapping was also observed for commonly used anode current collectors as the metals have some solubility for Li. Conducting boron-doped diamond electrodes were however seen to be resistant to Li diffusion and are therefore recommended as viable current collectors for anodes handling metallic lithium (i.e. Li-alloys and Li metal).
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| 12. |
- Rehnlund, David, 1986-, et al.
(författare)
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Lithium-Diffusion Induced Capacity Losses in Lithium-Based Batteries
- 2022
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Ingår i: Advanced Materials. - : John Wiley & Sons. - 0935-9648 .- 1521-4095. ; 34:19
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Forskningsöversikt (refereegranskat)abstract
- Rechargeable lithium-based batteries generally exhibit gradual capacity losses resulting in decreasing energy and power densities. For negative electrode materials, the capacity losses are largely attributed to the formation of a solid electrolyte interphase layer and volume expansion effects. For positive electrode materials, the capacity losses are, instead, mainly ascribed to structural changes and metal ion dissolution. This review focuses on another, so far largely unrecognized, type of capacity loss stemming from diffusion of lithium atoms or ions as a result of concentration gradients present in the electrode. An incomplete delithiation step is then seen for a negative electrode material while an incomplete lithiation step is obtained for a positive electrode material. Evidence for diffusion-controlled capacity losses is presented based on published experimental data and results obtained in recent studies focusing on this trapping effect. The implications of the diffusion-controlled Li-trapping induced capacity losses, which are discussed using a straightforward diffusion-based model, are compared with those of other phenomena expected to give capacity losses. Approaches that can be used to identify and circumvent the diffusion-controlled Li-trapping problem (e.g., regeneration of cycled batteries) are discussed, in addition to remaining challenges and proposed future research directions within this important research area.
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| 13. |
- Rehnlund, David, 1986-, et al.
(författare)
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Lithium trapping in alloy forming electrodes and current collectors for lithium based batteries
- 2017
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Ingår i: Energy & Environmental Science. - : Royal Society of Chemistry (RSC). - 1754-5692 .- 1754-5706. ; 10:6, s. 1350-1357
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Tidskriftsartikel (refereegranskat)abstract
- Significant capacity losses are generally seen for batteries containing high-capacity lithium alloy forming anode materials such as silicon, tin and aluminium. These losses are generally ascribed to a combination of volume expansion effects and irreversible electrolyte reduction reactions. Here, it is shown, based on e.g. elemental analyses of cycled electrodes, that the capacity losses for tin nanorod and silicon composite electrodes in fact involve diffusion controlled trapping of lithium in the electrodes. While an analogous effect is also demonstrated for copper, nickel and titanium current collectors, boron-doped diamond is shown to function as an effective lithium diffusion barrier. The present findings indicate that the durability of lithium based batteries can be improved significantly via proper electrode design or regeneration of the used electrodes. © The Royal Society of Chemistry 2017.
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| 14. |
- Rehnlund, David, 1986-, et al.
(författare)
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Lithium Trapping in Alloy forming Electrodes and Current Collectors for Lithium based Batteries
- 2018
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The next generation of lithium based batteries can be expected to be based on lithium alloy forming anode materials which can store up to ten times more charge than the currently used graphite anodes. This increase in the charge storage capability has motivated significant research towards the commercialization of anode materials such as Si, Sn and Al. These alloy forming anode materials are, however, known to exhibit significant capacity losses during cycling. This is typically ascribed to the volume expansion associated with the formation of the lithium alloys (the volume expansion is e.g. about 280 % for Li3.75Si) resulting in electrode pulverization as well as continuous solid electrolyte interphase (SEI) layer formation [1-3]. While significant progress has been made to decrease the volume expansion problems by the use of e.g. nanoparticles, nanorods and thin films, and/or capacity limitations [1-3], capacity losses are still generally seen [4,5]. This and previously published data suggest that the phenomenon may be due to another effect and that this in fact could stem from lithium trapping in the electrodes [6-8].In the present work it is demonstrated (based on e.g. elemental analyses of cycled Sn, Al and Si electrodes) that lithium trapping can account for the capacity losses seen when alloy forming anode materials are cycled versus lithium electrodes, see Figure 1. It is shown that small amounts of elemental lithium are trapped within the electrode material during the cycling as a result of a two-way diffusion process [8] causing the lithium to move into the bulk material even during the delithiation step. This phenomenon, which can be explained by the lithium concentration profiles in the electrodes, makes a complete delithiation process very time consuming. As a result of the lithium trapping effect, the lithium concentration in the electrode increases continuously during the cycling. The experimental results also show that a similar effect can be seen also for commonly used current collector metals such as Cu, Ni and Ti. The latter means that these metals are unsuitable as current collector materials for lithium alloy forming materials in the absence of a thin layer of boron doped diamond serving as a lithium diffusion barrier layer [8].References1 M. N. Obrovac and V. L. Chevrier, Chem. Rev., 2014, 114, 11444.2 X. Su, Q. Wu, J. Li, X. Xiao, A. Lott, W. Lu, B. W. Sheldon and J. Wu, Adv. Energy Mater., 2014, 4, 1300882.3 J. R. Szczech and S. Jin, Energy Environ. Sci., 2011, 4, 56.4 G. Zheng, S. W. Lee, Z. Liang, H-W. Lee, K. Yan, H. Yao, H. Wang, W. Li, S. Chu and Y. Cui, Nat. Nanotechnol., 2014, 9, 618.5 K. Yan, H-W. Lee, T. Gao, G. Zheng, H. Yao, H. Wang, Z. Lu, Y. Zhou, Z. Liang, Z. Liu, S. Chu and Y. Cui, Nano Letters, 2014, 14, 6016.6 G. Oltean, C-W. Tai, K. Edström and L. Nyholm, J. Power Sources, 2014, 269, 266.7 A. L. Michan, G. Divitini, A. J. Pell, M. Leskes, C. Ducati and C. P. Grey, J. Am. Chem. Soc., 2016, 138, 7918.8 D. Rehnlund, F. Lindgren, S. Böhme, T. Nordh, Y. Zou, J. Pettersson, U. Bexell, M. Boman, K. Edström and L. Nyholm, Energy Environ. Sci., 10 (2017) 1350.
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| 15. |
- Rehnlund, David, 1986-, et al.
(författare)
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Lithium trapping in microbatteries based on lithium- and Cu2O-coated copper nanorods
- 2018
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Ingår i: ChemistrySelect. - : Wiley. - 2365-6549. ; 3:8, s. 2311-2314
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Tidskriftsartikel (refereegranskat)abstract
- Microbatteries based on three-dimensional (3D) electrodes composed of thin films of Li and Cu2O coated on Cu nanorod current collectors by electrodeposition and spontaneous oxidation, respectively, are described and characterised electrochemically. High-resolution scanning electron microscopy (HR-SEM) data indicate that the Li electrodeposition resulted in a homogenous coverage of the Cu nanorods and elemental analyses were also used to determine the amount of lithium in the Li-coated electrodes. The results show that 3D Cu2O/Cu electrodes can be cycled versus 3D Li/Cu electrodes but that the capacity decreased during the cycling due to Li trapping in the Cu current collector of the 3D Li/Cu electrode. These findings highlight the problem of using copper current collectors together with metallic lithium as the formation of a solid solution yields considerable losses of electroactive lithium and hence capacity.
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| 16. |
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| 17. |
- Rehnlund, David, 1986-, et al.
(författare)
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Nanowired electrodes as outer membrane cytochrome-independent electronic conduit in Shewanella oneidensis
- 2022
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Ingår i: iScience. - : Cell Press. - 2589-0042. ; 25:2
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Tidskriftsartikel (refereegranskat)abstract
- Extracellular electron transfer (EET) from microorganisms to inorganic electrodes is a unique ability of electrochemically active bacteria. Despite rigorous genetic and biochemical screening of the c-type cytochromes that make up the EET network, the individual electron transfer steps over the cell membrane remain mostly unresolved. As such, attempts to transplant entire EET chains from native into non-native exoelectrogens have resulted in inferior electron transfer rates. In this study we investigate how nanostructured electrodes can interface with Shewanella oneidensis to establish an alternative EET pathway. Improved biocompatibility was observed for densely packed nanostructured surfaces with a low cell-nanowire load distribution during applied external forces. External gravitational forces were needed to establish a bioelectrochemical cell-nanorod interface. Bioelectrochemical analysis showed evidence of nanorod penetration beyond the outer cell membrane of a deletion mutant lacking all outer membrane cytochrome encoding genes that was only electroactive on a nanostructured surface and under external force.
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| 18. |
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| 19. |
- von Fieandt, Linus, et al.
(författare)
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Corrosion properties of CVD grown Ti(C,N) coatings in 3.5 wt-% NaCl environment
- 2018
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Ingår i: Corrosion Engineering, Science and Technology. - 1478-422X .- 1743-2782. ; 53:4, s. 316-320
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Tidskriftsartikel (refereegranskat)abstract
- The corrosion behaviour of Titanium carbonitride (Ti(C,N)) films grown by chemical vapour deposition was analysed in artificial sea water environment. From potentiodynamic polarisation curves, two passivation zones were detected, which originated from an initial oxidation of TiC and TiN to TiO2 followed by growth of the TiO2 layer upon increased polarisation. X-ray photoelectron spectroscopy analyses verified the mechanism by detecting a gradual decrease in Ti(C,N) peaks accompanied by a gradual increase of oxidised Ti (e.g. TiO2). It was likewise found that carbon in TiC mainly decomposes into carbonate species while the nitrogen in TiN remains elemental and likely escapes as nitrogen gas. Accordingly, Ti(C,N) behaves like a superposition of TiC and TiN with their individual oxidation behaviour, resulting in a highly corrosion resistant material.
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| 20. |
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