Acoustic emission histometry for battery material research

Acoustic emission histograms consisting of the rate of acoustic events as a function of time were described to characterize metal oxide-based materials in nonaqueous lithium cells. Samples examined by acoustic emission were manganese (di) oxides dried at 150 degrees C or heated at 400 degrees C (crystalline materials), PbSiO3 and SnSiO3 - glass (noncrystalline materials). The number of acoustic events due to the fracture of particles during lithiumion insertion reaction were monitored together with the operating voltages of these materials in nonaqueous lithium cells as a function of time, called acoustic emission histometry. Each sample was well characterized by this method. The power spectra of acoustic events were also examined and the possibility of acoustic emission spectroscopy was described. The significance of introducing an acoustic emission technique to insertion materials research for advanced lithium batteries was also described in terms of characteristic feature of insertion materials, mechanical fracture, and cycle life.