Energy storage system discharge mechanism

The amount of energy stored in a device as a percentage of its total energy capacity Fully discharged: SoC = 0% Fully charged: SoC = 100% Depth of discharge (DoD) The amount of energy that has been removed from a device as a percentage of the total energy capacity K. Webb ESE 471 6 Capacity

K. Webb ESE 471 9 Efficiency Another important performance characteristic is efficiency The percentage of energy put into storage that can later be extracted for use All storage systems suffer from losses Losses as energy flows into storage Losses as energy is extracted from storage K. Webb ESE 471 10 Round-Trip Efficiency

This study demonstrates the critical role of the space charge storage mechanism in advancing electrochemical energy storage and provides an unconventional perspective for designing high-performance anode materials for lithium-ion batteries.

Two primary figures of merit for energy storage systems: Specific energy Specific power Often a tradeoff between the two Different storage technologies best suited to different applications depending on power/energy requirements Storage technologies can be compared graphically on a Ragone plot Specific energy vs. specific power

Energy stored in many different domains Input and output energy is electrical Three-phase AC power Conversion is required between the storage domain and the electrical domain Transformer Power conversion system (PCS) K. Webb ESE 471 27 System Configurations – Mechanical Mechanical storage Pumped hydro, flywheels, compressed air

A schematic diagram showing the rate-dependent lithium storage mechanism in the artificially constructed mixed conductor electrode is given in Fig. 5, which also demonstrates the strong relevance of the space charge storage mechanism in designing high-performance, fast-charging materials.