China has seen a string of electric vehicles (EV) catching fire in its streets in recent months. Three prominent instances come to mind – one in May 2020 and two in August 2020. All three incidents involved GAC Aion sedans.
The Aion is GAC’s first EV offering, and the Guangzhou-based automaker gets its battery supply from China’s premier battery service, CATL. While GAC has not revealed the cause of all fire incidents, the latest fire which transpired on August 23 started in the battery manufactured by CATL.
The Chinese battery-maker supplies NCM 811 batteries to the GAC Aion. These batteries contain a fixed ratio of Nickel, Cobalt, and Manganese. The ‘811’ in its name stands for the NCM ratio – 80% Nickel, 10% Cobalt, 10% Manganese.
According to the Korean Herald, the ratio of Nickel in a battery is directly proportional to its energy density but inversely proportional to its stability. This means that a battery with a high concentration of Nickel is unstable and holds the possibility of damage.
An industry source for the Herald said, “The yield rate of CATL’s battery factory is reported at 45-55 percent, meaning that almost half of CATL’s batteries are defective. There could have been an issue when CATL tried to increase the ratio of Nickel.”
Nickel levels rising in global battery recipes
Korean EV battery-maker SK Innovation is planning to supply NCM batteries to Ford F-150 Pickup trucks in the near future. These batteries will reportedly contain 95% Nickel.
LG Chem, South Korea’s battery supplier to Tesla Model 3, is reportedly trying to make NCMA (Nickel Cobalt Manganese Aluminium) batteries that will hold a 90% concentration of Nickel.
CATL, another battery supplier to Tesla EVs, announced its collaboration with Mercedes-Benz last week. The duo is planning to develop a harmonic relationship to produce more efficient batteries in the European EV market.