Thermal runaway on 18650 lithium-ion batteries containing cathode materials with and without the coating of self-terminated oligomers with hyper-branched architecture (STOBA) used in electric vehicles

Four types of commercial E-One Moli 18650 lithium-ion batteries at full-charged state were subjected to confinement tests. The average exothermic onset temperature was measured to be (159.1 +/- 8.3) A degrees C. Adiabatic temperature rise was measured to be (498.4 +/- 25.6) A degrees C which corresponded to the enthalpy changes of (19.7 +/- 1.5) kJ. Maximum self-heat rate were determined to have an average value of 11,412.8 A degrees C min(-1) with the range from 6354.0 to 15,192.0 A degrees C min(-1). Lithium-ion batteries composed of cathode materials made of LiNixMnyCozO2 have been demonstrated to exhibit the calamitous characteristics of thermal runaway if they rise above the crucial temperature of (204.8 +/- 16.5) A degrees C. Surface coating of self-terminated oligomers with hyper-branched architecture (STOBA) upon cathode materials was unable to prevent the uncontrollable thermal runaway under external heating in these lithium-ion batteries.