Seminar, TERANISHI Takashi (Okayama University).

Secondary batteries with drastically enhanced power densities, i.e., capacity with faster charging/discharging times, will enable excellent acceleration and better fuel saving in cars of the automotive industry. Those batteries are thus promising candidates to power next-generation vehicles.
A breakthrough involving ferroelectricity to assist ultrahigh rate capability could be recently performed at Okayama University. It is related with the use in the batteries of ferroelectric barium titanate, BaTiO3 (BT), nanoparticles as an artificial solid electrolyte interfaces (SEIs), synthesized via a simple sol–gel route [1, 2]. The talk will be focused on the drastic enhancement of the high charge-discharge rate capability for Li ion batteries obtained by using ferroelectricity driven Li+ induction effect. The enhanced properties will be discussed in terms of the ferroelectricity contribution investigated by in-situ analysis such as electrochemical impedance spectroscopy [3] and X-ray absorption fine structure (XAFS).

[1] T. Teranishi et al., Appl. Phys. Lett. 105, 143904 (2014). [2] T. Teranishi et al., ECS Electrochem. Lett., 4 (2015). [3] T. Teranishi et al., Jpn. J. Appl. Phys., 54, 10NB02 (2015).

Significantly improved high rate capability
for the ferroelectric BaTiO3 - LiCoO2 composites
--- 1 mol% BaTiO3 (BT) decorated specimen exhibits
the highest capacity, 146 mAh/g, at 10C rate
(6 min full cha- and discharge), which was as high
as 238% of the bare LC.