Understanding Charge Transport and Storage Mechanisms in Electrochemical Energy Storage Devices using in Operando Small Angle Neutron Scattering

Rechargeable batteries and electrochemical supercapacitors are two of the most promising technologies to power mobile electronics, electric vehicles and large-scale grid storage. These techniques are facing some issues, i.e. cost, safety, cycle life, energy and power density, that hinder their applications, especially in transportation and stationary electrical energy storage. Molecular-level understanding of transport and storage mechanisms of electrolyte ions in electrodes and electrolyte solutions under operating electrochemical conditions is essential to design next generation materials. Small angle neutron scattering (SANS) has become an indispensable tool to provide key insights across length scales from 1 to 200 nm and kinetics on time resolution spanning from seconds to hours. This technique benefits from the adjustable contrast via deuteration of solvents or electrolytes; non-destructive due to the high penetrating power of neutrons. It also provides statistically meaningful measurements over the total volumes of illumination within complex sample environments and functional devices under varying experimental conditions. In this talk, I will highlight the applications of SANS in the characterization of electrodes and electrolytes in the past decade. The limits and future development direction of this technique for the operando characterization are also discussed.