New Measurement Technique That May Improve Batteries
Despite how common batteries are, they are not simple systems and their complexity makes it difficult to find all the avenues to improve them. For example, we do not fully understand how the electrodes behave while in use, in part because we have limited abilities to measure how heat can affect deformations due to stress. Researchers at Purdue University have recently developed a new experiment that can do just that.
The new measurement technique is based on Raman spectroscopy, which traditionally uses a laser to catch the vibrations of a crystal lattice, to determine the chemical composition of a material. What the researchers have done is added the ability to make nanomechanical measurements and to test it, they used microscale silicon cantilevers. The cantilevers had a stress applied to them and were heated from 25 ºC to 100 ºC. The results showed that the heat increased the deformation of the surface and near-surface structure, because the heat weakened the bonds between the atoms.
During normal use, batteries will heat up and the electrodes within will also swell and contract, which is why understanding how heat impacts the effects of stress. Something else that makes this technique particularly valuable for studying batteries is that Raman spectroscopy uses lasers, and thus does not need any sensors within the harsh insides of a battery.
Source: Purdue University