Kristian Bastholm Knudsen

Ph.D. Student

Phone: +45 21641412


The influence of CO2 poisoning on overvoltages and discharge capacity in non-aqueous Li-Air batteries

PhD information

Project Title: Investigation of Performance and Lifetime Limiting Effects in Li-air Battery Cells
Advisor(s): Johan Hjelm, Søren Højgaard Jensen, & Peter Holtapples
University: Technical University Of Denmark
Department: Energy Conversion and Storage
Commencement: December 2012

Technical Information

Synthesis techniques: Wittig polymerization, Suzuki Coupling, Hay Coupling, Photo Coupling by radical induced transfer mechanism, Atom-transfer radical Polymerization, Electrospinning
Analytical techniques: Scanning electron microscopy (SEM), Infrared spectroscopy (FTIR), Ultraviolet-visible spectroscopy (UV-VIS), Flourscence spectroscopy, Liquid chromatography (HPLC), Dynamic light scattering (DLS)
Electrochemical techniques: Chronoamperometry, Chronopotentiometry, Cyclic Voltammetry (CV), Pulse Voltammetry, Differential Pulse Voltammetry, Square Wave Voltammetry, Electrochemical Impedance Spectroscopy (EIS)

Description of PhD project

The project is a part of the ReLiable consortium comprising of the Danish Technical University (DTU Energy Conversion), Haldor Topsøe A/S, Stanford University, University of Southern Denmark and the battery management systems vendor Lithium Balance.

In my Ph.D., a combination of electrochemical and spectroscopic characterization techniques will be applied to a series of model- and promising Li-air cells in order to identify limiting reaction mechanisms. The three focus areas are:
1. Identify performance limiting reaction mechanisms during the nucleation, growth, and degradation of the electrodeposited layers at the cathode. This will be investigated by probing the conductivity of thin Li2O2 layers by monitoring the heterogeneous electron transfer kinetics of well-known outer-sphere redox couple at an electrode coated with thin Li2O2 layers.
2. Characterization of the fundamental electrochemical limiting factors affecting the Li-electrode/electrolyte interphase.
3. Identification of additional performance limiting reaction mechanisms in fully fabricated Li-air cells.


In 2012 I received a masters in Chemical Engineering from Aalborg University, DK, and currently I am a Ph.D. Student at the Department of Energy Conversion and Storage at the Technical University of Denmark.

My masters involved identification and synthesis of superhydrophobic polymers for membranes as emulsion separations. The project lead to a novel type of membrane displaying high efficiencies due to an enhanced hydrophobicity, partly due to a fiber like morphology introduced by electrospinning and partly by the choice polymer. I was so fortunate, that part of this work, was conducted at The University of Akron, OH, USA.

In December 2012, I was accepted as a Ph.D. at DTU, where my studies, so far, are on the fundamental aspects of the Li- and Na-O2 batteries.

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