Revealing the Impact of Fast Charge Cycling on the Thermal Safety of Lithium-Ion Batteries

Abstract

The safety of the degraded lithium-ion batteries has an essential impact on second life application. This study systematically investigates the thermal safety changes of lithium-ion batteries after deep aging under the fast charge aging path and reveals the degradation mechanisms caused by fast charge cycling. Lithium plating is the primary degradation mechanism, which thickens the solid electrolyte interface film, causes the loss of active lithium and electrolyte, and leads to a significant increase in impedance and a dramatic decrease in capacity. Therefore, compared with the fresh cells, the heat generation rate increases, while the total heat generation is reduced for aged cells. Besides, the thickened solid electrolyte interface film has lower thermal stability, decreasing the self-heating temperature for aged cells. Furthermore, thermal runaway results of partial cells prove that fast charge cycling reduces the thermal stability of the anode, which further proves that the thermal runaway-triggering temperature decrease is the result of the combination of the anode–electrolyte and anode–cathode reactions. Moreover, fast charge cycling reduces the lithium plating potential upon overcharging, which leads to the occurrence of side reactions in advance, creating the ratio of side reaction heat increase of aged cells for thermal runaway triggering. In addition, the loss of active materials reduces the maximum temperature and maximum temperature rise rate of the aged cell. The findings can provide references for battery safety management system optimization and safer battery screening.

High‐Voltage and Fast‐Charge Electrolytes for Lithium‐Ion Batteries

“…These adverse factors may change the conductivity of the electrolyte and lead to the degradation of lifetime. [14,15] The relationship between degradation mechanism and thermal safety characteristics was showed orderly in Figure 1. [15]…”

“…[14,15] The relationship between degradation mechanism and thermal safety characteristics was showed orderly in Figure 1. [15]…”

Heat Generation and Degradation Mechanism of Lithium-Ion Batteries during High-Temperature Aging

“…In addition, some researchers have also studied the effect of aging on the heat generation characteristics of lithium-ion batteries during charging/discharging. Zhang found that the total heat generation decreased while the heat generation rate increased significantly during the discharge process under the fast charge aging path . Zhang found that electrical abuse, such as overcharge and overdischarge, could significantly increase the heat generation during charging/discharging .…”

“…Zhang found that the total heat generation decreased while the heat generation rate increased significantly during the discharge process under the fast charge aging path. 31 Zhang found that electrical abuse, such as overcharge and overdischarge, could significantly increase the heat generation during charging/discharging. 32 Huang found that the larger the charge/discharge rate is, the more the heat generation is.…”

Enhancement of Columbic Efficiency and Capacity of Li-Ion Batteries using a Boron Nitride Nanotubes-Dispersed-Electrolyte with High Ionic Conductivity

“…7−11 However, due to some inherent limitations, they suffer from long-lasting detrimental loss of capacity of the LIBs. 12,13 In this regard, the electrolyte formulation strategy comes into play, where different additives are added to the conventional electrolytes in order to improve the battery performance. 14−18 Commonly, the electrolyte additives usually comprise of functional molecules that are preferentially involved in the interfacial redox process thereby prior to the electrolytes.…”