Carbon Materials with Hierarchical Pore Structure for Electrochemical Energy Storage Devices
The efficient storage and release of energy in electrochemical devices (e.g., batteries or electrical double-layer capacitors) is crucial to move from energy supply based on fossil fuels or nuclear power towards renewable sources such as wind, water, or solar energy. High surface area carbon materials play an important role in their electrodes because they combine a large number of active sites for electrochemical processes, high electric conductivity, and high electrochemical stability. We apply carbon materials with well-defined hierarchical pore architectures (i.e., pore structural units that have a pore structure themselves) in electrical double-layer capacitors and lithium batteries. Each pore system of the carbon materials contributes to efficient operation with its individual advantages. Very small pores with only a few nanometers in size can increase the electrochemical activity. Larger pores can provide transport ways for the electrolyte and provide rapid access to the smaller pores. This increases the speed of energy storage and energy release. The main research goals are to enhance the energy- and power density of such devices and to get a better understanding for the fundamental electrochemical processes.