Kinetic pathways of ionic transport in fast-charging lithium titanate

• DOI: 10.1126/science.aax3520
• Publication Date: 2020-02-28T00:05:20Z
• Authors: Wei Zhang; Dong-Hwa Seo; Tina Chen; Lijun Wu; Mehmet Topsakal; Yimei Zhu; Deyu Lu; Gerbrand Ceder; Feng Wang
• Keywords: Lithium titanate; Metastability; Limiting

Fast-charging batteries typically use electrodes capable of accommodating lithium continuously by means solid-solution transformation because they have few kinetic barriers apart from ionic diffusion. One exception is titanate (Li4Ti5O12), an anode exhibiting extraordinary rate capability apparently inconsistent with its two-phase reaction and slow Li diffusion in both phases. Through real-time tracking Li+ migration using operando electron energy-loss spectroscopy, we reveal that facile transport Li4+x Ti5O12 enabled pathways comprising distorted polyhedra metastable intermediates along boundaries. Our work demonstrates high-rate may be accessing the energy landscape above ground state, which fundamentally different mechanisms ground-state macroscopic This insight should present new opportunities searching for electrode materials.