Volume 2, Issue 1, Pages 155-167 (January 2018) Limiting Internal Short-Circuit Damage by Electrode Partition for Impact-Tolerant Li-Ion Batteries  Michael Naguib, Srikanth Allu, Srdjan Simunovic, Jianlin Li, Hsin Wang, Nancy J. Dudney  Joule  Volume 2, Issue 1, Pages 155-167 (January 2018) DOI: 10.1016/j.joule.2017.11.003 Copyright © 2017 Elsevier Inc. Terms and Conditions

Joule 2018 2, 155-167DOI: (10.1016/j.joule.2017.11.003) Copyright © 2017 Elsevier Inc. Terms and Conditions

Figure 1 Schematic for Mechanical Abuse-Tolerant Battery Design (A) Schematic showing predetermined breakable pattern in the battery electrodes. (B) The mechanically impacted part of the battery is separated upon prescribed deformation from the rest of the battery. This design limits the battery capacity that can be discharged through the isolation subregions to less than the capacity that causes sufficient I × R heating to initiate thermal runaway. Joule 2018 2, 155-167DOI: (10.1016/j.joule.2017.11.003) Copyright © 2017 Elsevier Inc. Terms and Conditions

Figure 2 Experimental Proof of Concept with Pouch Batteries (A) Schematic for a pouch cell shorted at the corner. (B) Thermographic image for a standard single-layer pouch cell at 1 s after shorting at the corner. (C) OCV of the battery in (B) during the short-circuit test. (D) Schematic for a modified battery design in which the corner is completely isolated electrically from the rest of the battery but shares the separator and electrolyte with the rest of the battery. (E) Thermographic image for a cell described in (D) at 1 s after shorting. (F) OCV for both corner and large portions of the battery shown in (D) and (E). Joule 2018 2, 155-167DOI: (10.1016/j.joule.2017.11.003) Copyright © 2017 Elsevier Inc. Terms and Conditions

Figure 3 Contour Plots of Li-Ion Concentration (mol/cm3) in the Solid Phase across the Segmented Electrodes during the End of the Discharge Process (A) Current collectors are isolated, but electrode materials are intact. (B) Current collectors and cathode electrodes are isolated with an anode electrode in place. (C) Current collectors and electrodes are completely isolated. Initial Li+ concentration in graphite was 66% of maximum concentration in all cases. Joule 2018 2, 155-167DOI: (10.1016/j.joule.2017.11.003) Copyright © 2017 Elsevier Inc. Terms and Conditions

Figure 4 Design and Function of the “Slitted” Electrodes (A) The slits pattern used in this study. (B) Schematic tearing associated with in-plane tensile loading. (C and D) Simulations of (C) uniaxial and (D) biaxial tension of thin copper foil with slits based on the pattern shown in (A) using FEM. (E) Snapshot at an intermediate time for a sphere shape pressing into an electrode with slits. In (C), (D), and (E) the colors denote the effective plastic strain. (F) Drawing for the clicker die used to introduce slits to the electrodes. Joule 2018 2, 155-167DOI: (10.1016/j.joule.2017.11.003) Copyright © 2017 Elsevier Inc. Terms and Conditions

Figure 5 Testing the Efficacy of the Slit Design for Electrolyte-free Cells (A) Photograph of the indentation test configuration used in this study; inset shows a schematic for the experimental setup. (B) OCV of AA battery connected to the electrolyte-free cells (as shown in the schematic) as function of time and stroke for both standard and modified cells. (C and D) Postmortem photographs after the indentation test for “slitted” (C) and standard (D) cells. The broken fragments covered by the magnifying glass symbol in (C) and (D) are shown at higher magnification on the left. Joule 2018 2, 155-167DOI: (10.1016/j.joule.2017.11.003) Copyright © 2017 Elsevier Inc. Terms and Conditions

Figure 6 Standard Battery Compared with Modified Battery (A) Precycling voltage profile for both standard (blue) and modified (red) cells cycled at C/10 for the first five cycles and then cycled at C/5 (inset shows capacity versus cycle number for the same results). (B) OCV during the indentation test for both standard and modified cells. (C and D) Photographs of modified (C) and standard (D) cells after the indentation test. (E) Capacity versus cycle number for the modified cell before and after the indention test. Joule 2018 2, 155-167DOI: (10.1016/j.joule.2017.11.003) Copyright © 2017 Elsevier Inc. Terms and Conditions