Energy Storage and Energy Conversion devices are both used to fill the need for portable as well as renewable power. Specific technologies are batteries, capacitors, fuel cells and solar cells. In commercial devices, these are often used in combination as part of a power system.
The evolving need requires the improvement in capability to provide pulse-power, long run-time and cycle life. Often power sources also have engineering constraints of volume and weight. New materials and advancements of engineering play a key role in meeting the market demand.
The power available from a device is defined by the product of its voltage and current. The voltage of a single device is defined by its specific chemistry. The current of a single device is defined by its size (electrode area).
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Li-ion batteries are today’s leading technology in this space, driven by their high operating voltage, up to 5 Volts. Other technologies, Li-Air, provide higher theoretical capacity operation.
Localized techniques, available on the VersaSCAN platform, are at the fore-front of research to characterize the Li-intercalation mechanisms and Solid-Electrolyte Interface (SEI) formation.
Commonly used techniques used for Batteries studies are Cyclic Voltammetry, Charge & Discharge, Capacity vs Cycle time, State of Charge/Health & etc
Once a fuel cell has been designed, it is typical to characterize its performance by DC polarization experiments using a low current galvanodynamic scan as the signal, measuring the voltage response, and by high current pulse experiments, again measuring the voltage response. In addition to DC techniques, fuel cells and fuel cell stacks are often characterized by electrochemical impedance spectroscopy. These results can provide information about diffusion and the total cell impedance at different DC currents.
Dielectric materials are non-conductors of electricity (electrical insulators) that are able to be highly polarized by an electrical field (this is expressed as the material’s dielectric constant). Charges within dielectric materials can be displaced from an equilibrium position by an electric field, and in some cases the charges may also be aligned to the applied field, but do not pass through the material. On removal of the electric field, the material returns to its original state and the time taken to do this is referred to as the relaxation period which is a characteristic of the dielectric material. Typical tests involve applying a varying electrical field (AC waveform), and monitoring the relaxation of the material as a function of its permittivity (capacitance and conductance) vs. the applied AC frequency.
The results of a good analysis depends on the quality of the sample preparation. Thus extremely important to consider all the individual milling parameters in order to achieved a good sample preparation such as:
Feed size, intrinsic material properties, volume of the sample, grinding time and desired final particle size, any abrasion of the grinding parts and lastly its costs.