In Situ Thermal Runaway Detection in Lithium-Ion Batteries with an Integrated Internal Sensor

Abstract

Thermal safety is of prime importance for any energy-storage system. For lithium-ion batteries (LIBs), numerous safety incidences have been roadblocks on the path toward realizing high-energy-density next-generation batteries. Solutions, viz. electrolyte additives, shut-off separators, and exotic coatings, have limited scope in their operating voltage window, response time, and performance. Various temperature monitoring devices have been tested out with their limitations. Here, we report in situ sensing of thermal signatures from the anode of a typical LIB using an internal resistance temperature detector (RTD). Solid electrolyte interface (SEI) comprised of ROCO 2 Li, (CH 2 OCO 2 Li) 2 and ROLi is formed on the surface of a graphite anode, and its decomposition releases enormous heat during thermal runway events. Sensing the temperature from the anode gives direct access to the heat liberated in thermal runaway, including SEI decomposition related heat generation. External short circuit (ESC) and overcharge tests were conducted to trigger the thermal runaway event, and temperature of 36.4 and 48.4 °C were recorded using internal RTDs, which were 9 and 20 °C higher than with external RTD, respectively. Interestingly, internal RTD has detection ability for 90% temperature rise 14 times faster than compared to the external RTD. Modeling of simulated tests explained the occurrence of different regimes during thermal runaway events initialed by ESC and overcharge. Furthermore, multimode calorimetry (MMC) for LIB with internal RTD yielded more endothermic peaks beyond 150 °C due to the presence of three-dimensional (3D)-printed polylactic acid (PLA) support. Overall 1.75 kJ g −1 of generated heat was measured using MMC, which is significantly lower than LIB without an RTD sensor. The RTD-embedded assembly acts as a passive safety device while stationed inside the battery. Using thermal signatures from RTD, an advanced battery management system can lead to a conducive LIB, which would be a safer powerhouse for high-energy-density applications such as in the automotive industry and high-energy grid storage.

Critical-Point-Dried, Porous, and Safer Aramid Nanofiber Separator for High-Performance Durable Lithium-Ion Batteries

“…The cells opened up around 219 °C for PP compared to 185 °C for CPD-ANF. This may be due to the electrolyte phase change that occurs at T > 80 °C . The peaks for the PP cell appeared more exothermic compared to those for CPD-ANF.…”

Mechanistic Elucidation of Electronically Conductive PEDOT:PSS Tailored Binder for a Potassium‐Ion Battery Graphite Anode: Electrochemical, Mechanical, and Thermal Safety Aspects

“…Also, in LIBs, thermal runaway is typically initiated by exothermic SEI decomposition between 100 and 150 °C. [ 79–85 ] However, previous work using KPF 6 based electrolytes has shown that in KIBs, the SEI actually has a protective effect, shielding intercalated potassium from participating in reactions with the electrolyte, and shifting the onset temperature upward. [ 86 ] Indeed, we find the more robust SEI provided herein by KFSI shifts the exothermic peak upward from 100 to 169 °C for the wetted, potassiated PVDF anode (Figure 8a).…”

“…It is worth mentioning as well, that overall heat generation of the charged, wetted KIB anode is less than that of LIBs, with a similar, or even higher onset temperature, suggesting KIBs may be a safer alternative with a rational selection of electrolyte, binder, and cathode. [79][80][81][82][83][84][85]…”

Operando Monitoring of Electrode Temperatures During Overcharge‐Caused Thermal Runaway

“…The measuring capability of the internal RTD depends on its ability to sustain the electrochemical environment of LIBs, which has been shown in our previous work. [ 2,26 ] It has also been shown that temperature gradients exist in the thickness direction of pouch cells. [ 27–29 ] This temperature gradient would be higher for cells with more electrode layers, which creates an opportunity for an internal RTD to detect LIB thermal runaway earlier.…”