Meaning
Internal deformation metric measures the variation in lattice spacing caused by structural flaws or atomic displacements within single crystal domains. Unlike macrostrain that acts over the whole particle, crystallite microstrain quantifies shifts that occur at the sub-micrometer scale within individual grains. This value identifies the density of point defects and dislocations that impact the movement of lithium ions through the lattice.
Lattice Variation
Inconsistencies in the d-spacing between atomic layers result from chemical inhomogeneities or thermal legacies left after calcination. Peak broadening in diffraction patterns provides the mathematical basis for calculating the extent of these variations. Higher values of crystallite microstrain indicate a lattice that is physically stressed before any electrochemical cycling begins.
Capacity Fade
Energy storage capacity drops as the density of internal defects creates sites where active ions become permanently trapped. While ideal crystals allow for free movement, high microstrain levels indicate disordered regions that impede diffusion. Reducing these internal forces through careful annealing steps leads to higher efficiency in high power applications.
Material Health
Measurements taken after multiple charge cycles show how the lattice accumulates damage over time. Changes in crystallite microstrain indicate the onset of mechanical fatigue before visible cracks appear on the surface. Lowering initial strain levels increases the number of cycles a material tolerates without substantial performance loss.
