Understanding Lithium Iron Phosphate for Better Lithium-Ion Batteries
Lithium iron phosphate (LiFePO4, or LFP) is one of the newer materials being used in lithium-ion batteries, and it is known to be safer and longer-lasting than the lithium cobalt oxide (LiCoO2) compound used in smart phones, laptops, and other consumer electronics. A barrier to the material's widespread adoption has been that the process by which lithium ions move in and out of LFP as the battery stores and releases its energy is not well understood. Now, researchers at Sandia National Laboratories have confirmed the particle-by-particle mechanism by which lithium ions move in and out of electrodes made of LFP. Their findings could lead to better performance in lithium-ion batteries in electric vehicles, medical equipment, and aircraft. In this video clip, materials scientist Josh Sugar describes the technical approach he and colleagues took to analyze LFP.
Transcript
00:00:00 after we've cycled the battery we take very thin slices of the battery where we can see the electrode particles the individual particles that make up the pieces of the battery that charge and discharge those thin slices are ultra micro toned and we take those thin slices and then we study them in two ways
00:00:19 first we go to the advanced light source and we look at them with the scanning transmission x-ray microscope this microscope has a very high energy resolution and as a result of that we're able to see the lithium distribution in each particle at a specific state of charge of the battery then we bring them to this lab where we
00:00:39 use the electron microscope which has a very high spatial resolution with the electron microscope we're able to see the individual boundaries of all the particles and see how the particles are distributed and then relate that same arrangement of particles to how the lithium is distributed and those two pieces of information
00:00:58 together help us understand what's happened during a charge or discharge cycle of the battery