R-019

Zenonas Jusys

zenonas.jusys@kit.edu

Helmholtz Institute Electrochemical Energy Storage Ulm (HIU), D-89081, Ulm, Germany

Karlsruhe Institute of Technology (KIT), D-76021, Karlsruhe, Germany

Theodor von Grotthuss – a contemporary scientist:  his impact on modern energy conversion and storage

220th Anniversary of the First Theory of Electrolysis by Theodor von Grotthuss highlights the importance of his visionary insights to the physical chemistry, in particular, electrochemistry, and to natural sciences in general. Based on a rather trivial (though modern by that time) research equipment, such as a Volta’s pile or an electrolyser bath, and a rather limited existing scientific knowledge available, he was able to formulate the basic principles of water electrolysis even prior the development of the theory of dissociation to ions (“particles”, or “matter fragments”), or a discovery of electron (“electrical fluid”), the water molecules being aligned in the “chains” between the electrodes, exchanging their component parts instantly and mutually [1,2]. Such an atomistic insight to the macro-scale process was clearly ahead of his time. It took more than one century for the further developments in chemistry and physics for re-wording the original Grotthuss’ idea as the proton hopping between the hydronium ions conjugated into a network via the hydrogen bonding. This present understanding enabled development of the proton conductive polymer membranes, such as Nafion®, where the proton hopping between the sulfonic groups, attached to the polymer backbone, ensures the ionic conductivity of the membrane and water transport in polymer electrolyte fuel cells and electrolysers [3], both being the state-of-the-art devices for the energy conversion. A proton-coupled electron transfer is also a key theory of the electrocatalytic reactions [4]. In water-in-salt electrolyte batteries, the electrochemical stability window of water can largely be extended by breaking the hydrogen bonds due to lack of free water molecules, the water being involved mainly in the hydration shell of the ions [5]. In single ion conducting polymer electrolyte batteries, the dendrite growth at the metal Li anode, lead by the free diffusion of Li+ ions, can largely be mitigated by their hopping between the anionic groups, attached to the polymer backbone [6]. The relevance of the proton/ion hopping mechanism was confirmed by a number of modern in situ and operando techniques, including the synchrotron facilities, as well as by employing powerful computational resources, though originally it was predicted by Theodor von Grotthuss more than two hundred years ago, thus making him a cutting-edge scientist even nowadays.   

1. C.J.T. Grotthuss, Mémoire sur la décomposition de l’eau et des corps qu’elle tient endissolution à l‘aide de l‘électricité galvanique. Rome, 1805.

2. B. Jaselskis et al., Bull. Hist. Chem., 2007, 32, 119-128.

3. M. Eikerling, et al., in Adv. Polym. Sci., Fuel Cells I. Springer-Verlag Berlin Heidelberg, 2008, 215, 15–54.

4. M.T.M. Koper, Chem. Sci., 2013, 4, 2710–2723.

5. J. Han, et al., Nano Energy 77 (2020) 105176; Z. Khan, et al., Adv. Mater. 2023, 2300369.