Sigmoidal current collector for lithium-ion battery

Abstract

In the current study, we investigated sigmoidal current collector in lithium-ion battery (LIB). Traditionally, the active material in an LIB electrode is coated on a flat current collector. By rendering the current collector sigmoidal-shaped, cracking and debonding of active material layer could be promoted, which would considerably increase the internal impedance, as the LIB is mechanically abused, beneficial to thermal-runaway mitigation. The energy absorption capacity is also improved, enabling multifunctional LIB cell design. This technique has important relevance to large-sized LIB systems, for which cell robustness and fire safety are prioritized.Published by AIP Publishing. [http://dx.

Safety Issues in Lithium Ion Batteries: Materials and Cell Design

“…Plenty of efforts are made to design low resistance electrode in these aspects, such as current collector (CC) optimization (Wang et al, 2017b,c;Lin et al, 2018a;Feng et al, 2019a), electrode porous structure design (Chen et al, 2016a;Fritsch et al, 2018), and so on. Although most works on CC optimization focuses on ESR reduction and rate performance improvement by surface roughening (Wang et al, 2017c) or 3D metal foam adopting (Fritsch et al, 2018), while it also has direct effect on the safety performance. Qiao's group found that upon external loading, heat generation of damaged LIB is heavily dependent on the failure mode of the CC, therefore, by efficient surface notch design on the CC, short circuit of the cell could be effectively eliminated (Wang et al, 2017b).…”

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.…”

Effect of notch depth of modified current collector on internal-short-circuit mitigation for lithium-ion battery

“…We recently investigated thermal-runaway mitigation mechanisms triggered by mechanical processes. For instance, adding a small amount of damage initiators into electrode [19][20][21] could promote widespread damages in electrodes under impact. The significant increase in internal impedance could suppress the ISC formation.…”