Browsing by Author "Nisula, Mikko"
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Item Al2O3 coating grown on Nafion membranes by atomic layer deposition(2015-12-01) Toikkanen, Outi; Nisula, Mikko; Pohjalainen, Elina; Hietala, Sami; Havansi, Hannele; Ruotsalainen, Jussi; Halttunen, Sakari; Karppinen, Maarit; Kallio, Tanja; Department of ChemistryNafion membranes were shown to be suitable substrates for atomic layer deposition (ALD) process. ALD utilising trimethyl aluminum as a precursor leads to well reproducible formation of smooth single-sided Al2O3 coating on the membranes. Physicochemical and mechanical properties of the coated membranes were compared to those of the unmodified ones. The coating reduced water uptake and thus also conductivity. Moreover, the Al2O3 coating decreased the oxygen permeability of the membrane by 10 % and the methanol permeability 30-50 %. The mechanical properties of the Nafion® membrane were improved. The resulting membranes were successfully applied in hydrogen fuel cells, direct methanol fuel cells and microbial fuel cells. In the microbial fuel cell, the Al2O3 coated membrane showed stable performance during long-term measurements of more than 100 d and doubled power densities in comparison to a cell equipped with a pristine membrane. The membrane modification strategy has potential for improving the performance of various types of membrane fuel cells and could be used for several types of functional membranes containing active groups for ALD growth.Item Alkali- ja maa-alkalimetalleihin perustuvat metalli-orgaanisen runkorakenteen ohutkalvot ALD/MLD-menetelmällä(2016-10-04) Penttinen, Jenna; Nisula, Mikko; Kemian tekniikan korkeakoulu; Karppinen, MaaritMetalli-orgaaniset runkorakenteet (MOF) soveltuvat niiden huokoisuudesta, muunneltavuudesta ja kiteisyydestä johtuen moniin käyttökohteisiin. Alkali- ja maa-alkalimetalleihin perustuvat MOF-rakenteet soveltuvat esimerkiksi kaasun varastoimiseen, sensoreiksi ja akkuihin elektrodimateriaaleiksi. Tämä diplomityö vertailee alkali- ja maa-alkalimetalleihin perustuvia metalli-orgaanisia runkorakenteita. MOF-rakenteen kasvatus ohutkalvomuotoon luo uusia sovelluskohteita. Mikroakuissa orgaanisen elektrodin vaatimuksena on ohutkalvon kolmiulotteinen rakenne, mikä lisää sen pinta-alaa, jolloin tehotiheys on suurempi ja varauksen kuljettajan diffuusioreitti lyhempi. Yhdistetyllä atomi- ja molekyylikerroskasvatusmenetelmällä (ALD/MLD) voidaan kasvattaa laadukasta ohutkalvoa kolmiulotteiselle substraatille. Diplomityön kokeellisessa osuudessa tavoitteena oli kasvattaa natriumiin, kaliumiin ja magnesiumiin perustuvia kiteisiä metalli-orgaanisen runkorakenteen ohutkalvoja yhdistetyllä ALD/MLD-menetelmällä. Orgaanisina lähtöaineina kasvatuksissa käytettiin tereftalaattihappoa ja 3,5-pyridiinidikarboksyylihappoa. Ohutkalvonäytteiden paksuutta, kiteisyyttä ja koostumusta analysoitiin. Näytteiden kiteisyyttä ja stabiilisuutta kosteus- ja lämpökäsittelyissä tutkittiin. Tuloksia vertailtiin keskenään ja kirjallisuuslähteisiin. Kokeellisessa osuudessa löydettiin kuusi uutta MOF-ohutkalvorakennetta.Item Atomic/molecular layer deposition and electrochemical performance of dilithium 2-aminoterephthalate(Royal Society of Chemistry, 2020-02-07) Heiska, Juho; Nisula, Mikko; Rautama, Eeva-Leena; Karttunen, Antti J.; Karppinen, Maarit; Department of Chemistry and Materials Science; School services, CHEM; Inorganic Materials Chemistry; Inorganic Materials ModellingControl of the redox potential of lithium terephthalate Li2TP anode material is demonstrated by functionalizing its terephthalate backbone with an electron-donating amino group; this lowers - as intended - the redox potential of Li2TP by 0.14 V. The two Li-organic electrode materials, Li2TP and Li2TP-NH2, are fabricated as crystalline thin films from gaseous precursors using the atomic/molecular layer deposition (ALD/MLD) technique. The amino-functionalized material possesses a previously unknown crystal structure, addressed here by applying the USPEX evolutionary algorithm for the structure prediction and then LeBail fitting of the experimental XRD pattern based on the predicted structure model. The ALD/MLD fabrication yields in situ lithiated active electrode materials without any conductive additivies or binders and thus allows a straightforward evaluation of their intrinsic electrochemical properties. Comparison between Li2TP and its amino-functionalized derivative reveals inferior capacity retention and rate capability characteristics for the latter, which somewhat counterveils the pros-and-cons balance between the two Li-organic electrode materials. From galvanostatic cycling experiments and post-mortem XRD and SEM analysis, the issue with Li2TP-NH2 is revealed to be in the morphology changes occurring during the discharge/charge cycling.Item Atomic/Molecular Layer Deposition of an All-Solid-State Thin-Film Battery Based on Organic Electrode Materials(Aalto University, 2018) Nisula, Mikko; Kemian ja materiaalitieteen laitos; Department of Chemistry and Materials Science; Laboratory of Inorganic Chemistry; Kemian tekniikan korkeakoulu; School of Chemical Technology; Karppinen, Maarit, Prof., Aalto University, Department of Chemistry and Materials Science, FinlandAll-solid-state Li-ion batteries in thin-film format are currently the most promising concept for the energy storage needs of miniature electronic devices. Their applicability is however restricted by their inherently poor energy and power densities. By using 3D substrates, the effective surface area and thus the energy density could be markedly increased. Atomic layer deposition (ALD) is one of the few methods capable in producing conformal layers on such complex structures. As the basic research on new ALD processes for Li-containing thin films is only in early stage, the true impact of the ALD technique in the Li-ion battery field is yet to be demonstrated. The aim of this theses was to advance the field with the introduction of novel deposition processes for each of the active components of a thin-film Li-ion battery. An ultimate goal was to manufacture a fully functional all-solid-state thin-film battery. For each material, the process design needs to take into account the fundamental difficulties related to lithium-based ALD chemistries. Additionally, by avoiding the use of metal components other than Li in the materials, the environmental impact of the newly designed and fabricated thin-film battery could potentially be reduced. For the solid electrolyte, a novel thermal-ALD process was developed for one of the most promising thin-film battery electrolyte material, i.e. lithium phosphorus oxynitride (LiPON). Due to its complex composition, it had been considered highly challenging compound for the ALD synthesis. In this thesis, the key innovation was the use of a novel ALD precursor, diethyl phosphoramidate. In combination with lithium bis(trimethylsilyl)amide, the quaternary target material could be deposited with a simple binary ALD process. The conformality on high-aspect-ratio substrates was confirmed and the measured ionic conductivity value is among the highest reported for ALD-grown solid electrolytes. For the electrode materials, a completely new approach was demonstrated. By utilizing combined atomic/molecular layer deposition (ALD/MLD) technique the range of available electrode materials was broadened to those based on conjugated carbonyl systems. Based on their fully organic backbones, such lithium organic electrode materials should be less harmful than their inorganic counterparts. The negative electrode material, lithium terephthalate, was known as one of the top performing organic electrode materials, whereas a completely novel material, dilithium-1,4-benezenediolate (Li2Q), was developed to function as the positive electrode. Excellent rate performance was demonstrated for both materials; in particular, charge/discharge times as low as 0.25 s were observed for Li2Q. Moreover, these materials were combined into an all-solid-state thin-film battery that was able to undergo extended charge/discharge cycling.Item Atomic/Molecular Layer Deposition of Lithium Terephthalate Thin Films as High Rate Capability Li-Ion Battery Anodes(2016) Nisula, Mikko; Karppinen, Maarit; Department of ChemistryWe demonstrate the fabrication of high-quality electrochemically active organic lithium electrode thin films by the currently strongly emerging combined atomic/molecular layer deposition (ALD/MLD) technique using lithium terephthalate, a recently found anode material for lithium-ion battery (LIB), as a proof-of-the-concept material. Our deposition process for Li-terephthalate is shown to well comply with the basic principles of ALD-type growth including the sequential self-saturated surface reactions, a necessity when aiming at micro-LIB devices with three-dimensional architectures. The as-deposited films are found crystalline across the deposition temperature range of 200-280 degrees C, which is a trait highly desired for an electrode material but rather unusual for hybrid inorganic-organic thin films. Excellent rate capability is ascertained for the Li-terephthalate films with no conductive additives required. The electrode performance can be further enhanced by depositing a thin protective LiPON solid-state electrolyte layer on top of Li-terephthalate; this yields highly stable structures with capacity retention of over 97% after 200 charge/discharge cycles at 3.2 C.Item Atomic/Molecular Layer Deposition of s-Block Metal Carboxylate Coordination Network Thin Films(WILEY-V C H VERLAG GMBH, 2017-12) Penttinen, Jenna; Nisula, Mikko; Karppinen, Maarit; Department of Chemistry and Materials Science; Inorganic Materials ChemistryWe present novel atomic/molecular layer deposition (ALD/MLD) processes for the fabrication of crystalline inorganic-organic coordination network thin films with different s-block elements. Terephthalic acid is employed as the organic precursor. Such thin films could enable for example, next-generation battery, sensor and gas-storage technologies. The deposition processes fulfill the basic principles of ALD/MLD-type growth including the sequential self-saturated gas-surface reactions and atomic/molecular-level control for the film thickness, and yield crystalline thin films in a wide deposition temperature range. Structural characterization of the films is performed by grazing incidence X-ray diffraction (GIXRD) and Fourier-transform infrared (FTIR) spectroscopy. The data do not unambiguously prove but also do not rule out the crystal structures previously reported for the corresponding bulk samples. We moreover demonstrate the growth of crystalline thin films of a new terephthalate material with La as the metal component. Upon humidity treatments the Li, Na, K, Ba, and La terephthalate films remain unaffected while the Mg, Ca, and Sr terephthalate films reversibly absorb water molecules forming well-defined crystalline water-derivative phases.Item Effects of atomic layer deposited aluminum oxide coating on lithium iron phosphate(2012) Nisula, Mikko; Manner, Satu; Kemian laitos; Kemian tekniikan korkeakoulu; School of Chemical Engineering; Karppinen, MaaritOf the existing battery technologies, the lithium ion battery is unrivalled in terms of energy density and it has emerged as the primary energy provider for mobile electronic devices. However, the currently used Li-ion battery materials are unsuitable for large scale applications due to their price and safety issues and thus new materials are needed. One of the most prominent new positive electrode materials is lithium iron phosphate (LiFePO4), which is intrinsically safe and consists of elements that are cheap and non-toxic. However, one of the downsides of lithium iron phosphate is its sensitivity towards water. In the literature part of this thesis, the effects of atmospheric moisture and immersion in water on the structure and electrochemical properties of LiFePO4 are described. Additionally, the protective properties of various coating materials against water contaminated electrolyte are reviewed. In the experimental part, LiFePO4 powder and composite electrodes are coated with aluminium oxide using the atomic layer deposition (ALD) method. By means of thermo gravimetric and electrochemical measurements it is investigated whether such a coating can prevent the adverse effects of water during atmospheric exposure, when immersed in water and during the battery operation. Additionally, a preliminary investigation on the possibility of replacing the conventional polymer separator with an ALD-grown aluminium oxide layer is conducted. It is found out that while the aluminium oxide coating does not prevent the degrading effects of atmospheric moisture, it has a beneficial impact on the electrochemical performance. A thick enough coating seems to be able to fully prevent water contaminated electrolyte from reacting with the electrode material. The coating also improves the obtained capacities. Regarding the possibility to use an aluminium oxide as a separator layer, it is shown here that a layer with a suitable thickness prevents the electrodes from short-circuiting, but the electrochemical performance of such a cell is greatly hindered.Item Emergence of Metallic Conductivity in Ordered One-Dimensional Coordination Polymer Thin Films upon Reductive Doping(AMERICAN CHEMICAL SOCIETY, 2021-03-03) Nisula, Mikko; Karttunen, Antti J.; Solano, Eduardo; Tewari, Girish C.; Karppinen, Maarit; Minjauw, Matthias; Jena, Himanshu Sekhar; Van Der Voort, Pascal; Poelman, Dirk; Detavernier, Christophe; Ghent University; Department of Chemistry and Materials Science; Autonomous University of BarcelonaThe prospect of introducing tunable electric conductivity in metal-organic coordination polymers is of high interest for nanoelectronic applications. As the electronic properties of these materials are strongly dependent on their microstructure, the assembly of coordination polymers into thin films with well-controlled growth direction and thickness is crucial for practical devices. Here, we report the deposition of one-dimensional (1D) coordination polymer thin films of N,N′-dimethyl dithiooxamidato-copper by atomic/molecular layer deposition. High out-of-plane ordering is observed in the resulting thin films suggesting the formation of a well-ordered secondary structure by the parallel alignment of the 1D polymer chains. We show that the electrical conductivity of the thin films is highly dependent on their oxidation state. The as-deposited films are nearly insulating with an electrical conductivity below 10-10 S cm-1 with semiconductor-like temperature dependency. Partial reduction with H2 at elevated temperature leads to an increase in the electrical conductivity by 8 orders of magnitude. In the high-conductance state, metallic behavior is observed over the temperature range of 2-300 K. Density functional theory calculations indicate that the metallic behavior originates from the formation of a half-filled energy band intersecting the Fermi level with the conduction pathway formed by the Cu-S-Cu interaction between neighboring polymer chains.Item In situ lithiated quinone cathode for ALD/MLD-fabricated high-power thin-film battery(2018-01-01) Nisula, Mikko; Karppinen, Maarit; Department of Chemistry and Materials Science; Inorganic Materials ChemistryWe demonstrate that the high-capacity organic electrode material, p-benzoquinone, is able to sustain ultrahigh redox reaction rates without any conductive additives when applied as ultrathin layers in an all-solid-state thin-film battery setup, viable for e.g. high-performance power sources in microelectronic devices. The combined atomic/molecular layer deposition (ALD/MLD) technique employed for the fabrication allows the in situ deposition of the quinone cathode in its lithiated state. The LiPON solid electrolyte is fabricated by ALD as a remarkably thin layer down to 30 nm. Our proof-of-concept setup is able to reach 50% of the full capacity in less than 0.25 s, with energy/power densities of 108 mW h cm-3 and 508 W cm-3. These characteristics are of considerable promise towards bridging the gap between microbatteries and microsupercapacitors. Moreover, we demonstrate an all-ALD/MLD-made organic battery where the lithium quinone and LiPON layers are combined with a lithium terephthalate anode layer.Item Keraamiset diffuusionestomateriaalit muoveille(2009) Nisula, Mikko; Putkonen, Matti; Karppinen, Maarit; Kemian ja materiaalitieteiden tiedekunta; Linnekoski, JuhaItem Kiinteän elektrolyytin litiumioniakut(2014-04-28) Sarnes, Liisa; Nisula, Mikko; Kemiantekniikan korkeakoulu; Fabricius, GunillaItem Lithium Aryloxide Thin Films with Guest-Induced Structural Transformation by ALD/MLD(2017) Nisula, Mikko; Linnera, Jarno; Karttunen, Antti J.; Karppinen, Maarit; Department of Chemistry and Materials Science; Inorganic Materials Chemistry; Inorganic Materials ModellingCrystalline Li-organic thin films are grown with the atomic/molecular layer deposition (ALD/MLD) technique from lithium hexamethyldisilazide and hydroquinone. The as-deposited films are found to undergo a reversible structural transformation upon exposure to ambient humid air. According to density functional theory calculations, the guest-induced transformation may be related to an unsaturated Li site in the crystal structure.Item Litiumioniakkujen positiivielektrodimateriaalien pinnoitus atomikerroskasvatusmenetelmällä(2015-04-29) Ropponen, Artturi; Nisula, Mikko; Kemiantekniikan korkeakoulu; Fabricius, GunillaItem Metalli-orgaanisista runkorakenteista koostuvien ohutkalvojen valmistus ja käyttökohteet(2016-05-31) Haikkola, Eetu; Nisula, Mikko; Kemiantekniikan korkeakoulu; Karppinen, MaaritItem New s-Block Metal Pyridinedicarboxylate Network Structures through Gas-Phase Thin-Film Synthesis(WILEY-V C H VERLAG GMBH, 2019-09-02) Penttinen, Jenna; Nisula, Mikko; Karppinen, Maarit; Department of Chemistry and Materials Science; Inorganic Materials ChemistryThe combined atomic and molecular layer deposition (ALD/MLD) technique offers a unique way to build—both known and previously unknown—crystalline coordination polymer materials directly from gaseous precursors in a high-quality thin-film form. Here, we demonstrate the ALD/MLD of crystalline Li-, Na-, and K-based 3,5-pyridinedicarboxylate (3,5-PDC) thin films; the Li2-3,5-PDC films are of the known Li-ULMOF-4 crystal structure whereas the other as-deposited crystalline films possess structures not previously reported. Another exciting possibility offered by ALD/MLD is the deposition of well-defined but amorphous metal–organic thin films, such as our Mg-, Ca-, Sr-, and Ba-based 3,5-PDC films, which can then be crystallized into water-containing structures through a post-deposition humidity treatment. All together, the new metal–organic structures realized in this study through ALD/MLD comprise a majority of the (anhydrous and water-containing) members of the s-block metal 3,5-pyridinedicarboxylate family.Item Orgaaniset elektrodimateriaalit litiumioniakuissa(2016-12-24) Vähä-Pietilä, Erkka; Nisula, Mikko; Kemiantekniikan korkeakoulu; Fabricius, GunillaItem Organic electrode materials with solid-state battery technology(ROYAL SOC CHEMISTRY, 2019-01-01) Heiska, Juho; Nisula, Mikko; Karppinen, Maarit; Department of Chemistry and Materials Science; Inorganic Materials ChemistryThe quest for next-generation sustainable (resource-wise, safe and eco-friendly), high performance (light-weight and energy/power dense) and cost-efficient rechargeable energy storage devices has been catalyzing the research on new battery chemistries. In this research rush, organic electrode materials have ticked many of the wish-list boxes, but there are also a few obstacles to overcome, the two major ones being their intrinsically poor electronic conductivity and instantaneous dissolution into liquid electrolytes. In this critical review, we first provide the readers with a brief account of the various organic material families considered for electrode materials, with their particular benefits and problems. Then, using some basic concepts borrowed from the field of organic electronics we aim to gain a deeper insight into the conductivity of organics in electrochemical systems-an issue little discussed so far. To address the solubility issue we discuss-with some illustrative examples-the benefits and challenges possibly emerging by combining the organic electrodes with a solid electrolyte instead of the conventional liquid electrolyte. As one of the highlights we discuss thin-film microbatteries fabricated using the atomic/molecular layer deposition (ALD/MLD) technique, where ultrathin layers of the LiPON electrolyte are combined with lithium quinone and terephthalate electrodes. Such a thin-film configuration is intriguing in the sense that it does not contain any additives, thus serving as an ideal model system for fundamental studies.Item Organic lithium salts deposited with ALD for sustainable microbatteries(2017-06-13) Heiska, Juho; Nisula, Mikko; Kemian tekniikan korkeakoulu; Karppinen, MaaritLithium ion batteries are already an established technology and is widely used in microbatteries. The dimensions of the devices that utilize microbatteries have shrunk, while the power requirement has remained constant. Moving from 2D to 3D architectures is a viable way of increasing the capacity per area. A major problem with 3D architectures is the fabrication of pinhole free and uniform layers of active material. One solution is to use precise deposition techniques such as atomic layer deposition (ALD). Organic electrode materials are an interesting alternative to the inorganic electrode materials due to their high gravimetric and power density values. They can also be produced from abundant and sustainable resources. The structural diversity of the organic materials is immense and even small modifications change their chemical and electrochemical properties. The redox potential of organic electrode materials can be affected by adding an electron donating or withdrawing functional group. In this work, five different organic precursors 2-aminoterephtalic acid (TPA2A), 2-bromoterephtalic acid (TPABr), 2,5-dihydroxylterephtalic acid (TPA25OH), 2,5-pyridinecaboxylic acid (PDC25), and 3,5-pyridinecaboxylic acid (PDC35) were employed as the organic ALD precursors. The inorganic precursor was LiTHD (THD = 2,2,6,6-tetramethyl-3,5-heptanedione). The deposited thin films were characterized with X-ray reflectivity (XRR), grazing incidence X-ray diffraction (GIXRD), and Fourier transform infrared spectroscopy (FTIR). The electrochemical properties of the thin films were evaluated with cyclic voltammetry (CV) and galvanostactic cycling from a half cell containing metallic lithium counter electrode. Out of the deposited materials, the films Li2TP2A, Li2TP25OH, and Li2PDC35, were crystalline, while Li2PDC25, and Li2TPBr were amorphous as confirmed by GIXRD. The saturation of the growth was confirmed for Li2TP2A with XRR, while the growth linearity and ALD temperature window was examined quantitatively. The functional groups present in the molecules are not lithiated during the deposition. The electrochemical measurements revealed that the average redox potential was increased for electron withdrawing groups and decreased for electron donating groups. The change in potential was fairly moderate. The Li2TPBr films out performed other films to some extent, in respect to cycling capabilities and the effect on the redox potential.Item Toisen sukupolven keraamiset suprajohdekaapelit(2014-05-30) Penttinen, Jenna; Nisula, Mikko; Kemiantekniikan korkeakoulu; Fabricius, Gunilla
