Lithium-ion batteries have been increasingly demonstrated in reuse applications for environmental and economic reasons, and stationary energy storage systems (ESS) and mobile ESS are emerging as reuse applications for electric vehicle batteries. Most mobile ESS deployments are at large scales, necessitating experimental data on thermal runaway (TR) to ensure comprehensive safety. In this study, TR induction and suppression experiments were conducted using fully charged NCM-based batteries at the cell (750 Wh), module (7.5 kWh), and pack (74 kWh) levels. The stepwise TR experiments measured changes in temperature, voltage, heat release rate, volatile organic compound concentrations, and vent gas composition. The suppression experiments assessed the effective water injection rate, timing, and volume required to mitigate TR propagation. The results demonstrate that in the case of TR caused by thermal abuse, early detection of battery abnormalities is possible through monitoring pre-TR indicators, such as temperature and vent gas concentration. It was also confirmed that CO2 injections can effectively cool the battery without causing damage. Furthermore, it is proposed that rapid water injection, directly contacting the battery immediately after the onset of TR, can successfully prevent TR propagation.
1 December 2021 in Journal of the Electrochemical Society
Lithium-sulfur batteries (LSB) are highly promising candidates for next generation energy storage devices due to their high theoretical capacity and the low cost of sulfur. However, dissolution of lithium polysulfides (LPS) into electrolyte causes undesirable effects, resulting in loss of active materials, low Coulombic efficiency, and fast capacity fading. To address these issues, designed interlayers are inserted between a separator and S cathode to evaluate the effect of blocking of long chain LPS and catalytic conversion of LPS to Li 2 S 2 /Li 2 S on battery performance. In order to amplify the effect of interlayer, the Ni 2 P nanoparticles are electrochemically deposited on carbon fabric (CF) which exhibit excellent adsorption and conversion effect of LPS. A cell fabricated with the Ni 2 P@CF interlayer allows remarkable improvement in the capacity decay of 0.04% per cycle at 1C for 1000 cycles and outstanding high rate capability. The cell delivered a capacity retention of 64% employing a current density of 8 C.