Wireless induced effects and bipolar electrochemistry in energy storage systems
PhD Candidate: Marc Mosqueda
Date: Tuesday, 23 June 2026
Time: 11.00 AM
Venue: Sala d'Actes Carles Miravitlles and ONLINE (Register here)
Abstract
The main objective of this thesis is to elucidate the role of induced wireless bipolar electrochemistry in the field of energy storage, never tackled before in the field.
New applications for wireless electrochemistry have been found recently from wireless electrodeposition to oscillating reactions related to local changes in resistance of the bipolar electrode. If the material allows mixed conductivity and redox intercalation/deintercalation, asymmetric reactions achieved through the material create redox gradients with significant structures and effects on wireless neural electrostimulation or magnetoionics.
In particular, our observation of a great decrease in ohmic and charge transfer resistance for electrochemical cells, when immersing a conducting material in the electrolyte, suggests a significant possible improvement in battery design, with larger efficiencies, and enhanced power. Furthermore, wireless electrochemical synthesis of catalysts could be possible using simplified cells without direct wirings. In this thesis, the study of bipolar electrochemistry effects have focused on both chemical or electrochemical energy storage, following two fundamental lines in parallel, 1) The synthesis of specific nanostructures that facilitate energy harvesting/storage (photocatalysis using TiO2 to harvest solar energy for H2 production), and 2) The use of induced unwired bipolar electrodes within the electrolyte to engineer battery performance: the unwired induced anodes and cathodes formed in presence of external electric fields would modify cell resistance and offer additional charge transfer mechanisms within the battery, thus offering a new paradigm in battery performance, lifetime, and capacity improvement.
Therefore, we have specifically tested:
1) The synthesis of aligned nanostructures of TiO₂-nanotubes, through wireless anodization of titanium metal. TiO₂, with a band gap in the UV range may still raise its photocatalytic performance through doping that could improve its conductivity and photoactivity. Here, a secondary vacuum annealing after wireless synthesis, attempts to induce doping/structure defects to enhance the
photoactivity. Different arrangements of the Ti metal within the electric field may create different gradients in NT diameter/thickness, modifying activity. Once annealed under vacuum, intertwined anatase-rutile phases are observed, while several spectroscopic techniques demonstrate that sub-states appear facilitating transitions and increasing the separation of electron-hole charges generated photoelectrochemically. This is correlated with H₂ production and photoelectrochemical water splitting.
2) The effect of bipolar unwired electrodes in a battery is studied to determine the influence of induced polarization. Different configurations of bipolar electrodes are tested within three distinct batteries. Each type of battery includes specific factors like: having the redox active material in solid or soluble form, using systems with or without membrane, as well as different materials as unwired bipolar electrodes, with different electrochemical activity.
As this is the first study that applies bipolar electrochemistry to electrochemical energy storage systems, we have chosen widely studied systems to focus exclusively on the changes observed in batteries when bipolar electrodes are included: a Cu/Zn battery; a symmetrical Fe(CN)63-/Fe(CN)64- cell containing soluble redox components and a Zn-air alkaline reversible battery. Having active redox sites in solid state and in solution is evaluated, as well as the influence of the configuration of bipolar electrodes and the materials used in them. Electrochemical characterization experiments for each battery type are performed to reach full interpretation of bipolar electrodes influence and to verify the chemical changes observed. Simultaneous impedance measurements are carried out that show the evolution of the main physical effects of bipolar electrochemistry along charge and discharge. COMSOL simulations evaluate the given hypotheses.
In all cases, unwired bipolar electrodes lower battery-overpotentials and cell resistance, increase power, enhancing charge capacities fourfold in certain configurations. This strongly suggests the possible application of bipolar effects in batteries with longer autonomy distances, smaller weight or larger usage times in mobile or stationary applications.
Supervisors
- Nieves Casañ, ICMAB-CSIC
- Xavier Torrelles, ICMAB-CSIC
PhD Committee
- President: Pedro Gómez Romero, ICN2, Spain
- Secretary: Eva Maria Pellicer Vilà, UAB, Spain
- Vocal: Juan Sebastián Reparaz, ICMAB-CSIC, Spain
University: Universitat Autònoma de Barcelona (UAB)
PhD Programme: Materials Science
