Authors: J. Mandal, S. Du, M. Dontigny, K. Zaghib, N. Yu, Y. Yang.
Journal Link: Advanced Functional Materials 28 (36), 201802180 (2018).
Summary: In this work, we looked at Lithium Titanium Oxide (Li4Ti5O12), a promising material for battery anodes which is known to change from white to black when it is charged. We investigated the optical properties of Li4Ti5O12 across the visible to LWIR wavelengths (i.e. 0.4-14 µm), and found that the transition from white to black actually stretches all the way from the visible to the LWIR. We explore the potential physical mechanisms of the switching, and demonstrate that it can be used for radiative cooling and heating, and thermal camouflage.
Note: the original idea of investigating the Li4Ti5O12 was not mine, but that of my doctoral adviser, Dr. Yuan Yang. He had the hunch that the optical switching of the material can extend into the infrared, and asked me to optical characterize samples he had prepared. After confirming his hypothesis, I explored the physics of the optical transition, and the optical design aspects with the goal of achieving radiative cooling and thermal camouflage.