Internal-short-mitigating current collector for lithium-ion battery

Abstract

Mechanical abuse often causes thermal runaway of lithium-ion battery (LIB). When a LIB cell is impacted, radial cracks can be formed in the current collector, separating the electrode into petals. As separator ruptures, the petals on positive and negative electrodes may contact each other, forming internal short circuit (ISC). In this study, we conducted an experimental investigation on LIB coin cells with current collectors modified by surface notches. Our testing results showed that as the current collector contained appropriate surface notches, the cracking mode of electrode in a damaged LIB cell could be adjusted. Particularly, if a complete circumferential crack was generated, the petals would be cut off, which drastically reduced the area of electrode involved in ISC and the associated heat generation rate. A parameterized study was performed to analysis various surface-notch configurations. We identified an efficient surface-notch design that consistently led to trivial temperature increase of ISC.

Internal short circuit mitigation of high-voltage lithium-ion batteries with functional current collectors

“…As a result, the effective shorting resistance (r) is increased by more than one order of magnitude. 31 Even with the high voltage and the high specic energy of the LIB cells under investigation, because the inner area is only $10% of the total cell size, the heat generation of ISC is nearly undetectable.…”

“…31 While this nding is encouraging, there are still a couple of issues: rst, previously the modication of current collector was conducted by etching, which was timeconsuming and incompatible with the current LIB manufacturing methods. Second, there have not been any data about whether the modied current collector technique can be applied to higher-voltage higher-energy battery chemistry.…”

A multifunctional battery module design for electric vehicle

“…It was proposed that, as cylindrical battery cells are placed in parallel and confined by regular walls [8,9], a disintegrable structure can be formed, which provides sufficient flexibility to protect battery cells in a vehicle collision. A number of studies were performed on battery safety and robustness at the cell level [10][11][12][13][14][15]. Functional current collector (FCC) [10][11][12] was developed to isolate the damaged areas in a mechanically abused battery cell, which significantly decreased the heat generation rate.…”

“…A number of studies were performed on battery safety and robustness at the cell level [10][11][12][13][14][15]. Functional current collector (FCC) [10][11][12] was developed to isolate the damaged areas in a mechanically abused battery cell, which significantly decreased the heat generation rate. Thermally sensitive binder (TSB) [13,14] was developed to reduce the electronic conductivity once the battery was overheated, and thermal runaway retardant (TRR) [15] was employed to lower the ionic conductivity.…”

“…Thermally sensitive binder (TSB) [13,14] was developed to reduce the electronic conductivity once the battery was overheated, and thermal runaway retardant (TRR) [15] was employed to lower the ionic conductivity. The battery cells were typically tested through nail penetration, blunt impact or indentation [10][11][12][13][14][15]; in such tests, the cell case would largely deform and the active materials were internally shorted. In addition, computer simulation at the vehicle level [16] has demonstrated that strategic placement of battery pack could reduce the impact forces on occupants and minimize the damages of battery cells.…”