Daniel J. Noelle

Effects of additional multiwall carbon nanotubes on impact behaviors of LiNi0.5Mn0.3Co0.2O2 battery electrodes

This work introduces a new mechanically triggered thermal runaway mitigation mechanism. The homogenizer of electrode failure (HEF), multiwall carbon nanotube (MWCNT), was added into LiNi0.5Mn0.3Co0.2O2 (NMC532) battery electrodes. We have studied the effect of the HEF additive on the internal electrical resistance and the mechanical impact resistance of the electrodes. The additional MWCNTs reduced the internal electrical resistance of electrodes before mechanical abuse. Upon mechanical abuse, they could mitigate internal shorting and thermal runaway at normal battery working temperature.

Heat generation of mechanically abused lithium-ion batteries modified by carbon black micro-particulates

In the current study, we experimentally investigated the effects of carbon black micro-particulates (CBMP) on the temperature increase of lithium-ion battery coin cells subjected to nail penetration and blunt impact. The major difference between CBMP and regular carbon black additives is in particle size. The testing data showed that addition of 1 wt% of CBMP in the cathode and anode does not influence the cycle life, while can reduce the heat generation rate by nearly 50%, after the peak temperature is reached. Thermal treatment of the modified cells at 100 °C would further reduce the heat generate rate. The initial temperature increase rate, the maximum temperature, as well as the total energy dissipation are not affected. These findings shed light on thermal runaway mitigation of high-energy batteries.

Heterogeneous current collector in lithium-ion battery for thermal-runaway mitigation

Current collector accounts for more than 90% of the electric conductivity and ∼90% of the mechanical strength of the electrode in lithium-ion battery (LIB). Usually, current collectors are smooth metallic thin films. In the current study, we show that if the current collector is heterogeneous, the heat generation becomes negligible when the LIB cell is subjected to mechanical abuse. The phenomenon is attributed to the guided strain concentration, which promotes the separation of the forward and the return paths of internal short circuit. As the internal impedance drastically increases, the stored electric energy cannot be dissipated as thermal energy. The modification of current collector does not affect the cycling performance of the LIB cell. This finding enables advanced thermal-runaway mitigation techniques for high-energy, large-scale energy storage systems.

Mitigating thermal runaway of lithium-ion battery through electrolyte displacement

Alkanes are investigated as thermal-runaway retardants (TRR) for lithium-ion battery (LIB). TRR is a chemical that can rapidly terminate exothermic reactions in LIB. Under normal working conditions, TRR is sealed in separate packages in the LIB cell, and upon mechanical abuse, it is released to suppress heat generation. The alkanes under investigation include octane, pentadecane, and icosane, among which pentadecane has the highest thermal-runaway mitigation (TRM) efficiency. In nail penetration test on coin cells, ∼4 wt. % pentadecane reduced the maximum temperature by ∼60%; in impact test on pouch cells, ∼5 wt. % pentadecane reduced the maximum temperature by ∼90%. The high TRM efficiency of pentadecane is attributed to its high wettability to separator and its immiscibility with electrolyte. By forming a physical barrier between the cathode and anode, pentadecane interrupts lithium ion (Li+) transport and increases the charge transfer resistance by nearly two orders of magnitude. The diffusion rate of ...

Effects of electrode pattern on thermal runaway of lithium-ion battery

In the current study, through a set of nail penetration and impact tests on modified lithium-ion battery coin half-cells, we examine the effects of electrode pattern on the heat generation behaviors associated with internal shorting. The results show that the temperature profile is quite insensitive to the openings in cathode layer, which may be attributed to the high specific energy as well as the secondary conductive paths. This finding will considerably influence the study in the area of thermal runaway mitigation of energy storage systems.

Sigmoidal current collector for lithium-ion battery

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.

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

The safety of lithium-ion battery (LIB) becomes increasingly critical as the specific energy and cell capacity rapidly increase. Based on the modified current collector technique recently developed for nickel–cobalt–manganese active materials, here we investigate high-energy LIBs based on functional current collectors (FCC). Two high-voltage active materials were tested in our experiments: lithium-rich layered oxide (LRLO) and lithium nickel manganese oxide (LNMO). At the same time as a fully charged LIB cell is damaged, FCC isolates the internal short circuit (ISC) from the undamaged area; hence, the ISC-induced heat generation is drastically reduced to a negligible level. The electrochemical performance of FCC-based cells is nearly identical to that of reference cells.