Rutile nano-electrodes undergo structural changes during repeated battery operation
Using a combination of total scattering analysis and transmission electron microscopy, Christensen et al. investigate the atomic-scale structure of the rutile (TiO2) electrode during charge-discharge process. They demonstrated the phase-change behavior of rutile as it transformed from an ordered to a disordered state with repeated cycling.
Why do these nano-electrodes amorphize and not fracture?
On the theory front, we reasoned as to why the rutile nano-particles amorphized (phase-change behavior) instead of dissipating their stored elastic energy by electrode fracture. Our fracture analysis calculations estimated the critical size of rutile nano-particles below which fracture is suppressed to be ∼20 nm. The nano-particle sizes used in this experiment were about ~11nm.
- Christensen, C. K., Mamakhel, A., Balakrishna, A. R., Iversen, B. B., Chiang, Y. M., & Ravnsbæk, D. (2019).Order–disorder transition in nano-rutile TiO2 anodes: a high capacity low-volume change Li-ion battery material. Nanoscale, 11, 12347.