ИСТИНА

Electrochemical energy storage (supercapacitors, rechargeable batteries) and conversion (electrochemical water splitters, fuel cells) systems all deal with the electrochemical interfaces at which charge separation and chemical reactions occur. The evolution of the structure, composition and chemistry at the interfaces between electrodes and electrolytes affects all the functional parameters of the device including power and long-term performance stability. Ex situ studies provide only part of the information needed because the chemical reactions taking place during operation of the electrochemical devices result in intermediates and products that sometimes cannot be “quenched” for post-process studies. An in-depth understanding of the atomistic mechanisms underlying different electrochemical processes (electric double layer formation or Faradic processes involving heterogeneous electron or ion transfer) often requires recording large sets of data under operando conditions with temporal and, sometimes, spatial resolution. Thus, electrochemical studies nowadays face a double challenge in obtaining both the necessary information selectively from the electrochemical interfaces and in recording the data from operating systems. The analytical techniques capable of exploring the interfaces are still very limited. There are few surface-sensitive and bulk-sensitive tools, which might potentially address the problem. However, real electrochemical interfaces are buried, so that they are inaccessible directly to the common surface science tools. At the same time the bulk sensitive techniques suffer from a minor contribution of the interface to the signal. In this lecture, we attempt to review a range of tools that can be helpful in solving the above-mentioned problems. Attempts to implement traditional surface-sensitive tools with increased probing depth and/or minimized electrode or electrolyte layer thickness, techniques with intrinsic interface sensitivity (e.g. neutron reflectometry) and some efforts on adopting traditionally bulk-sensitive techniques for interface studies will be considered.