Sodium Ion Battery Hard Carbon Anode Precursor Selection Standards
Precursor selection for sodium ion hard carbon anodes dictates closed pore volume, surface area, initial coulombic efficiency, and landed material cost.
XRD D002 Measurement
Meaning
An analytical test method employs x-ray diffraction to calculate the average interplanar spacing between the graphene sheets in carbonaceous materials. Utilizing the xrd d002 measurement allows material scientists to evaluate the degree of graphitization in battery anode powders.
Physical Principle
The testing procedure directs a collimated x-ray beam onto a powder sample and records the intensity of the diffracted rays over a range of angles. Using Bragg’s Law, the angle of the d002 diffraction peak is converted into the distance between the carbon layers, measured in nanometers. This distance decreases as the carbon structure becomes more ordered, approaching the value of pure graphite at point three three five nanometers.
Sourcing Indicator
Cell manufacturers use this test to verify the quality and consistency of graphite supplied for anode production. A smaller spacing indicates a more graphitic structure, which provides higher electrical conductivity and better capacity for lithium intercalation. Procurement teams use this parameter to verify that the thermal treatment of synthetic graphite has reached the required temperature.
Analytical Limit
This measurement does not provide information about the surface chemistry or the pore structure of the carbon. It represents a bulk average and can miss localized amorphous regions within the sample.