Title: Internal configuration of prismatic lithium-ion cells at the onset of mechanically induced short circuit

Abstract

The response of Li-ion cells to mechanically induced internal electrical shorts is an important safety performance metric design. We assume that the battery internal configuration at the onset of electrical short influences the subsequent response and can be used to gauge the safety risk. We subjected a series of prismatic Li-ion cells to lateral pinching using 0.25", 0.5", 1", 2" and 3" diameter steel balls until the onset of internal short. The external aluminum enclosure froze the internal cell configuration at the onset of short and enabled us to cross-section the cells, and take the cross-section images. The images indicate that an internal electric short is preceded by extensive strain partitioning in the cells, fracturing and tearing of the current collectors, and cracking and slipping of the electrode layers with multiple fault lines across multiple layers. These observations are at odds with a common notion of homogeneous deformation across the layers and strain hardening of electrodes that eventually punch through the separator and short the cell. The faults are akin to tectonic movements of multiple layers that are characteristic of granular materials and bonded aggregates. As a result, the short circuits occur after extensive internal faulting, which implies significant stretchingmore » and tearing of separators.« less

Authors:

Wang, Hsin ^[1]; Simunovic, Srdjan ^[1]; Maleki, Hosein ^[2]; Howard, Jason N. ^[2]; Hallmark, Jerald A. ^[2]

---

+ Show Author Affiliations

1. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
2. Motorola Mobility, Lawrenceville, GA (United States)

Publication Date:

Fri Jan 01 00:00:00 EST 2016

Research Org.:

Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

Sponsoring Org.:

USDOE Office of Energy Efficiency and Renewable Energy (EERE)

OSTI Identifier:

1236581

Alternate Identifier(s):

OSTI ID: 1397331

Grant/Contract Number:  

AC05-00OR22725

Resource Type:

Accepted Manuscript

Journal Name:

Journal of Power Sources

Additional Journal Information:

Journal Volume: 306; Journal Issue: C; Journal ID: ISSN 0378-7753

Country of Publication:

United States

Language:

English

Subject:

25 ENERGY STORAGE