Ni-rich LiNi0.82Co0.15Al0.03O2(NCA) as a high specific capacity thermal battery cathode material

The applications for plug-in hybrid electric vehicles (PHEVs) and electrical vehicles (EVs) of Ni-rich NCA materials (LiNi x Co y Al z O 2 , x + y + z = 1, x > 0.6) were restricted owing to the potential safety hazard and capacity attenuation during cycle. Herein, we reported a new application of Ni-rich LiNi 0.8 Co 0.15 Al 0.05 O 2 in thermal battery with improved safety. At the current density of 100 mA cm −2 (10 C), the NCA cathode still showed a specific capacity as high as 541 mAh g −1 with a cut-off voltage of 1.2 V at 500 °C. Compared with the large current density discharge of lithium-ion batteries, the specific capacity of NCA at high-temperature excitation was far beyond the theoretical specific capacity (277 mAh g −1 ). It was mainly attributed to the special conversion reaction mechanism: 2 Li + Li 2 NiO 2 → 2 Li 2 O + Ni. Such a high specific capacity is promising as a cathode material for thermal battery.