Scaling relation between renormalized discharge rate and capacity in Na x CoO2 films

• 小林, 航

• 守友, 浩

• Yanagita, Ayumu

• Shibata, Takayuki

• Kobayashi, Wataru

• Moritomo, Yutaka

Abstract

Layered cobalt oxide, P2-Na x CoO2, is a prototypical cathode material for sodium-ion secondary battery. We systematically investigated the rate dependence of the discharge capacity (Q) in three thin films of Na 0.68CoO2 with different film thickness (d) and in-plane grain radius (r). With subtracting conventional voltage drop effect on Q, we derived an intrinsic rate dependence of Q. We found a scaling relation between the renormalized discharge rate (γ ≡ r 2/DT; D and T are the Na + diffusion constant and discharge time, respectively) and relative capacity (=Q/Q 0; Q 0 is the value at a low rate limit). The observed scaling relation is interpreted in terms of the Na + intercalation process at the electrolyte-Na x CoO2 interface and Na + diffusion process within Na x CoO2.

Journal

• APL Materials

  APL Materials 3 (10), 106104-, 2015-10

  AIP Publishing

Details

• CRID: 1050282677530995840
• NII Article ID: 120007135876
• ISSN: 2166532X
• HANDLE: 2241/00131816
• Web Site: https://tsukuba.repo.nii.ac.jp/records/36395
• Text Lang: en
• Article Type: journal article
• Data Source:
  • IRDB
  • CiNii Articles