Antiarrhythmische Therapie bei Patienten mit implantierbarem Cardioverter/Defibrillator- Ist diese medikamentöse Therapie gerechtfertigt?

Hintergrund: Die Implantation eines ICD ist ein etabliertes Therapieverfahren bei der Behandlung lebensbedrohlicher ventrikulärer Tachyarrhythmien (VT). Häufig besteht vor der Implantation eines ICD eine antiarrhythmische Begleittherapie oder es ist zur Reduktion der Inzidenz von VT-Episoden eine additive, medikamentöse Rhythmusbehandlung erforderlich. Wir untersuchten in unserem ICD-Kollektiv die Ursache und die Häufigkeit der antiarrhythmischen Behandlung.Methodik: Seit Anfang 2003 wurde bei 112 Patienten (Pt) ein ICD implantiert (mittlere Ejektionsfraktion (EF) 42 ± 17 %, 19 Frauen, mittleres Alter 61 ± 13 Jahre, 59 % KHK). Insgesamt erhielten 84 % der Pt Beta-Blocker.Ergebnisse: Zum Zeitpunkt der Implantation des ICD erhielten 16 Pt Amiodaron (Amio), 6 Pt Ca-Antagonisten, 2 Pt Sotalol und insgesamt 3 Pt Klasse I Antiarrhythmika. Eine Kombination von 2 Antiarrhythmika lag bei 2 Pt vor. Die Pt, welche nur mit Amio behandelt wurden, wiesen eine signifikant schlechtere EF auf, als das Restkollektiv (33 % vs 44 %, p Zusammenfassung: In unserem ICD-Kollektiv wurden 24 % der Pt mit Antiarrhythmika behandelt. Die Therapie war mit einer reduzierten Ejektionsfraktion assoziiert. Jedoch bestand keine Abhängigkeit der pharmakologischen Behandlung mit Amio und dem Auftreten paroxysmalen Vorhofflimmerns, der Auslösbarkeit von VTs in der elektro-physiologischen Untersuchung oder gar dem Auftreten von VT im Langzeitverlauf. Nach Implantation eines ICD sollte die antiarrhythmische Begleitmedikation kritisch eingesetzt werden, um Nebenwirkungen und besonders Dezelerationen lebensbedrohlicher VT und ihre Konsequenz zu vermeiden.</p

Nanoarchitectured Array Electrodes for Rechargeable Lithium- and Sodium-Ion Batteries

Rechargeable ion batteries have contributed immensely to shaping the modern world and been seriously considered for the efficient storage and utilization of intermittent renewable energies. To fulfill their potential in the future market, superior battery performance of high capacity, great rate capability, and long lifespan is undoubtedly required. In the past decade, along with discovering new electrode materials, the focus has been shifting more and more toward rational electrode designs because the performance is intimately connected to the electrode architectures, particularly their designs at the nanoscale that can alleviate the reliance on the materials' intrinsic nature. The utilization of nanoarchitectured arrays in the design of electrodes has been proven to significantly improve the battery performance. A comprehensive summary of the structural features and fabrications of the nanoarchitectured array electrodes is provided, and some of the latest achievements in the area of both lithium‐ and sodium‐ion batteries are highlighted. Finally, future challenges and opportunities that would allow further development of such advanced electrode configuration are discussed

Fabrication and characterization of 3D thin-film batteries

The technological fields of mobile devices, remote wireless sensors, implantable medical devices, smart cards and energy harvesters are rapidly evolving. A bottleneck in the development of such emerging systems is the energy storage component required for extended autonomous operation. Miniaturization of conventional batteries is limited by the use of particle materials and a liquid electrolyte. Commercially available planar (2D) thin-film solid-state batteries are intrinsically safe, can be charged quickly for thousands of cycles, and are available in the smallest form. Unfortunately, the thin-film electrodes in these batteries contain only a small amount of active electrode material, which results in a relatively low storage capacity. In order to increase the capacity of thin-film batteries, three-dimensional thin-film solid-state batteries are envisioned. By using high aspect ratio structures as the current-collector substrate, the amount of active material per footprint area can effectively be increased, while fast charging capabilities are retained. The main goal of this thesis was to fabricate and characterize titania-based thin-film electrodes for 3D thin-film batteries. Four main scientific goals were pursued: 1) Perform a fundamental study on the Li+-ion insertion/extraction properties of anatase versus amorphous TiO2 thin-films and on the influence of nanosizing. 2) Investigate doping of TiO2 thin-films to increase their rate-performance and Li-ion capacity. 3) Understand the impact of solid electrolytes on thin-film electrode performance. 4) Investigate conformal coating of TiO2 deposited by (spatial)-ALD on micropillar substrates. TiO2 was chosen as thin-film Li+-ion insertion anode, as it offers a high volumetric capacity, shows a small volume expansion upon lithiation, and can be conformally coated using atomic layer deposition (ALD). Unfortunately, when using the common anatase structure, the rate-performance is extremely poor. Even for nanosized films (i.e. 35 nm), it was shown that anatase did not provide satisfactory rate-performance. For the first time, the electrochemical properties of amorphous TiO2 (am-TiO2) were systematically compared with anatase, using cyclic voltammetry, galvanostatic charge/discharge and potentiostatic intermittent titration technique experiments (PITT). The performance could be improved multifold by using the amorphous TiO2 structure. As a result of the promising Li+-ion insertion properties of am-TiO2, nanosize am-TiO2 thin-films were deposited on a 3D (aperiodic) carbon nanosheet substrate, highlighting the conformal nature of ALD, and the concept of surface area enhancement for increasing the (footprint) capacity. Next, chlorine was investigated as a dopant for am-TiO2. By selecting TiCl4 as the Ti-precursor for the ALD process, Cl was incorporated during am-TiO2 deposition. The influence of the electrochemical properties as a function of Cl-content were investigated in detail. The rate-performance and storage capacity were found to improve with increasing Cl-contents. Compared to state-of-the art TiO2 from literature, Cl-doped amorphous TiO2 showed one of the highest storage capacity to date. To unravel the properties and promises of 3D thin-film batteries, optimal micropillar array designs and their theoretical capacities were simulated. The use of a large-scale applicable deposition technique (i.e. Spatial ALD or S-ALD) was investigated. Specifically, the aspect of conformal coating across a high-surface area micropillar array using S-ALD were studied and compared to conventional ALD. As a demonstration, Cl-doped am-TiO2 films were deposited on Si micropillar arrays and their electrochemical properties were investigated. Finally, TiO2 was combined with a LiPON solid-state electrolyte thin-film and electrochemical properties of the TiO2/LiPON stacks were investigated.Acknowledgements I Abstract IV Nederlandse samenvatting VI List of abbreviations IX List of symbols and constants X Table of contents XIII List of figures XVII List of tables XX Chapter 1 Introduction .............................. 1 1.1 Thin-film batteries for microstorage application 1 1.2 Principles and working mechanism of the LIB.......3 1.3 Planar and three-dimensional thin-film batteries .5 1.4 Anode candidates for 3D thin-film batteries ..... 7 1.5 TiO2 as Li+-ion storage electrode ............... 9 1.6 Outline ......................................... 12 References .......................................... 14 Chapter 2 Thin-film fabrication and electrochemical characterization tools .... 21 Abstract ............................................ 21 2.1 Spatial atomic layer deposition of TiO2 ..........22 2.2 Electrochemical setup ........................... 24 2.3 Cyclic voltammetry .............................. 25 2.4 Constant current lithiation and delithiation .... 27 2.5 Potentiostatic intermittent titration technique . 28 References .......................................... 32 Chapter 3 Electrochemical performance of amorphous versus anatase TiO2 thin-films for Li+-ion storage .............. 35 Abstract ............................................ 36 3.1 Introduction .....................................37 3.2 Material & methods .............................. 39 3.3 Results ......................................... 41 3.3.1 Structure and composition ..................... 41 3.3.2 Cyclic voltammetry to study of Li+-ion insertion and extraction .. 42 3.3.3 Rate-performance probed by constant current charge/discharge . 47 3.3.4 Determination of kinetic parameters by PITT ....51 3.3.5 Lithium insertion/extraction mechanisms ........57 3.4 Conclusions ..................................... 60 Supporting information ...............................62 Fitting of PITT current transients .................. 62 References .......................................... 65 Chapter 4 Nanostructured TiO2/carbon nanosheet hybrid electrode for high-rate thin-film lithium-ion batteries ....... 69 Abstract ............................................ 70 4.1 Introduction .................................... 71 4.1.1 Carbon nanosheets ............................. 71 4.1.2 TiO2/carbon nanosheet hybrid .................. 72 4.1.3 Substrate-attached TiO2 /CNS .................. 73 4.2 Experimental details ............................ 74 4.2.1 Preparation of vertically standing CNS on TiN/Si substrate. ......... 74 4.2.2 ALD of TiO2 on CNS. ........................... 74 4.2.3 Structural characterization ................... 75 4.2.4 Electrochemical testing of TiO2/CNS electrodes .75 4.3 Results and Discussion .......................... 76 4.3.1 Structure and morphology of as-prepared and TiO2-coated CNS . 76 4.3.2 Electrochemical activity of TiO2/CNS ...........80 4.3.3 Galvanostatic charge/discharge characteristics of CNS and TiO2/CNS ......................................................85 4.3.4 Rate capabilities ............................. 87 4.4 Conclusions ..................................... 89 Supplementary information............................ 90 References .......................................... 91 Chapter 5 Chlorine doping of amorphous TiO2 for increased capacity and faster Li+-ion storage ..................... 93 Abstract ............................................ 94 5.1 Introduction .................................... 95 5.2 Experimental section ............................ 97 5.2.1 Planar and micropillar substrates ............. 97 5.2.2 Spatial Atomic Layer Deposition of TiO2 ....... 97 5.2.3 Structural characterization ....................98 5.2.4 Electrochemical characterization............... 99 5.3 Results ........................................ 100 5.3.1 Spatial ALD of (chlorine-doped) TiO2 films ....100 5.3.2 Chemical analysis of chlorine-doped TiO2 films 101 5.3.3 Electrochemical performance of chlorine-doped TiO2 films ......106 5.3.4 Demonstration of Cl-doped am-TiO2 as 3D thin-film electrode ....113 5.3.5 Benchmarking of the 3D Cl-doped am-TiO2 electrode .................. 119 5.4 Summary and conclusions ........................ 121 Supplementary information .......................... 123 References ......................................... 130 Chapter 6 3D Thin-film solid-state batteries: Considerations on design and manufacturing ................... 137 Abstract......................... 138 6.1 Introduction ................................... 139 6.2 Experimental methods............................ 141 6.2.1 Planar and micropillar substrates ............ 141 6.2.2 Spatial Atomic Layer Deposition of TiO2 .......142 6.2.3 Atomic Layer Deposition of TiO2 .............. 143 6.2.4 Thickness and conformality characterization .. 143 6.2.5 Electrochemical characterization ............. 143 6.3 Results and discussion ......................... 145 6.3.1 Design considerations and theoretical capacity of micropillar structures ......................................................................................................... 145 6.3.2 Spatial ALD as a manufacturing tool for 3D thin-film electrodes 153 6.3.3 Interpretation of conformality results .........159 6.4 Conclusions ..................................... 163 Supplementary information ........................... 165 Commercial thin-film and coin cell batteries .........165 Theoretical capacity micropillars ....................165 Requirement of the spacing and second electrode thickness ............167 SEM thickness measurements .......................... 169 Approximating the exposure dose for conformal deposition ..................170 References .......................................... 173 Chapter 7 Nanoscaling of electrode/solid-electrolyte systems: LiPON/TiO2........................................................... 177 Abstract ............................................ 178 7.1 Introduction .................................... 179 7.2 Materials and methods ........................... 181 7.2.1 TiO2-LiPON deposition and composition ......... 181 7.2.2 Electrochemical characterization ...............182 7.3 Results and discussion .......................... 183 7.3.1 LiPON composition and sputter-induced lithiation of TiO2 ........ 183 7.3.2 Li+-ion insertion and extraction kinetics of LiPON/TiO2 ............. 186 7.3.3 Near-equilibrium thermodynamic and kinetic properties of LiPON/TiO2 probed by PITT ................................................ 189 7.4 Conclusions ..................................... 193 References .......................................... 194 Supporting information .............................. 197 Chapter 8 Conclusions and outlook ....................199 8.1 Amorphous TiO2 as insertion electrode for 3D thin-film batteries............................................ 199 8.2 Doping of am-TiO2 with chlorine ..................200 8.3 TiO2-LiPON interface ............................ 201 8.4 Towards full 3D thin-film batteries.............. 202 References .......................................... 203 Contributions ....................................... 205 Publications ........................................ 205 Conferences ......................................... 205nrpages: 229status: publishe

The Kinetics of Nanometer Sized TiO₂ Films as a Lithium-Ion Insertion Electrode

The miniaturization of autonomous wireless sensors, implantable devices and energy harvesters, has steadily been increasing in the last decades. However, the pace of miniaturization of batteries has been lagging behind, with typical sizes of batteries two to a thousand times larger than the corresponding microelectronic device1. To solve this problem, planar all-solid-state thin-film Li-ion micro-batteries have been developed and commercialized. Although they offer size reduction and a significant increase in power density compared to conventional rechargeable coin cells, the limitations due to diffusion resistances and mechanical integrity of such planar devices limits the maximum thickness of the active electrodes and consequently the capacity. To increase the energy density, ultra-thin films could be deposited on three-dimensional substrates thereby significantly increasing the power density and capacity, while preventing detrimental effects such as film cracking and delamination. For this, deposition techniques that can deposit conformably and pinhole-free on 3D structures is necessary. Atomic layer deposition (ALD) is therefore an interesting deposition technique, since structures with very high aspect ratios (~5000) can be coated2. However, to successfully design 3D (micro-)batteries, the properties of ultra-thin films have to be investigated. A material that shows high capacity (~200 mAh/g), especially upon nanostructuring, is TiO2. Such nanostructuring strategies include using nanoparticles3, nanotubes4 or nanoflakes5, but the characterization of a well-defined system, such as thin TiO2 films with the same length scale (5 - 35 nm), is still lacking. Therefore, in this work we electrochemically characterize TiO2 thin-films of 5 nm to 35 nm deposited with atomic layer deposition (ALD). Structure and morphology of the films were examined by transmission electron microscopy (TEM) and grazing-incidence X-Ray diffraction (GI-XRD), and showed that the crystal structure of as-deposited TiO2 changes from amorphous TiO2 for the 5 nm TiO2 films to anatase for the 35 nm TiO2films. Electrochemical characterization was done using cyclic voltammetry and galvanostatic charge/discharge. Cyclic voltammetry results shown in figure 1a clearly reflected the difference between lithium insertion/extraction into amorphous and anatase TiO2. Furthermore, scan rate dependent peak current measurements showed how the lithium diffusion behavior changed from semi-infinite diffusion for the 35 nm films to finite-length diffusion for the 5 nm films. The improved kinetics for thinner films were also captured by galvanostatic charge/discharge measurements. Figure 1b shows the volumetric capacity of lithiation; at a charging rate of 1C, 5 nm TiO2 had a reversible volumetric capacity of ~150 µAh cm-2 µm-1, which is even above the theoretical capacity of TiO2 (~142 µAh cm-2 µm-1). Comparatively, 35 nm TiO2 only achieved a capacity of ~50 µAh cm-2 µm-1. Upon increasing the charging rate to 200C (full theoretical charging in 18 seconds), 50% of the original capacity was retained (~75 µAh cm-2 µm-1) for 5 nm TiO2 and only 10% of the original capacity was retained for 35 nm TiO2 (~5 µAh cm-2 µm-1). These results highlight the great potential of TiO2thin-films as an electrode in 3D (micro-)batteries and are a good example how simply scaling of the electrode thickness can significantly enhance the volumetric capacity and rate-performance. References 1. T. S. Arthur et al., MRS Bull., 36, 523–531 (2011) 2. J. W. Elam, D. Routkevitch, P. P. Mardilovich, and S. M. George, Chem. Mater., 15, 3507–3517 (2003) 3. S. K. Das, M. Patel, and A. J. Bhattacharyya, ACS Appl. Mater. Interfaces, 2, 2091–2099 (2010) 4. G. F. Ortiz et al., Electrochim. Acta, 54, 4262–4268 (2009) 5. M.-C. Yang, Y.-Y. Lee, B. Xu, K. Powers, and Y. S. Meng, J. Power Sources, 207, 166–172 (2012) </jats:p

Investigation of the Li-ion insertion mechanism for amorphous and anatase TiO2 thin films

Titania is considered an interesting anode candidate for Li+-ion batteries, as it offers a high theoretical capacity (1280 mAh cm−3 or 336 mAh g−1) and long term cycling stability. Unfortunately, the most commonly investigated anatase structure never reaches the theoretical capacity at practical charging rates (i.e. above 1 C). In this work, we compare amorphous (am-TiO2) to anatase TiO2 thin-films, and investigate the exceptional performance of am-TiO2 as Li+-ion insertion electrode. An in-depth electrochemical characterization using cyclic voltammetry (CV), constant current lithiation and delithiation, and potentiostatic intermittent titration technique (PITT) is performed. From CV, the insertion and extraction kinetics of am-TiO2 is found to be unrestricted by diffusion, contrary to anatase. Based on our combined electrochemical results, two different mechanisms are formulated for anatase and am- TiO2. Whereas anatase is filled from the “top-down”, with a buildup of Li near the electrode/electrolyte interface, am-TiO2 shows a “bottom-up” filling mechanism. This discrepancy is ascribed to the difference in diffusion coefficient measured for am-TiO2 and anatase. This work highlights the differences of Li-ion insertion into amorphous TiO2 compared to anatase, and gives guidance on material development for high capacity and fast charging electrodes.status: publishe