Panasonic is preparing to mass produce large-format 4680 battery cells for Tesla, and facing new manufacturing challenges as part of that process, the head of the company's new consolidated battery division in a recent interview with Nikkei Asia.

"In terms of product development, the technological goals have largely been achieved," Kazuo Tadanobu, CEO of Panasonic's battery division, said. "But mass-producing them requires new techniques."

The 4680-format cells are substantially larger than the 2170-format cells Panasonic currently supplies to Tesla. They have about five times the capacity of 2170 cells, Tadanobu said. The 4680 size—46 millimeters wide by 80 millimeters long—was considered the optimal size when factoring in cost, the vehicles themselves, and other possibilities posed by cylindrical batteries," he said.

Cylindrical cells - Panasonic hinting at 4680 progress

Cylindrical cells - Panasonic hinting at 4680 progress

Tadanobu said Panasonic is working on 4680 cells "at Tesla's request," and said the automaker is the company's main priority. But Panasonic won't rule out working with other automakers, he said.

Panasonic last month revealed a prototype version of the 4680 cell and said that it aims for test production as early as March, with potential production later in the year.

That likely reflects a turnaround in thinking, as a top battery executive at the company earlier this year expressed some skepticism about the format, saying in a Bloomberg interview that bigger cells could help affordability, but noting that they posed overheating and fire risks.

Tesla Texas

Tesla Texas

Tesla featured 4680 cells at the center of its 2020 Battery Day presentation, claiming the cells would dramatically cut costs and that any production hurdles could be overcome.

Tesla still plans to use the 4680 cells starting with Model Y crossovers assembled in Texas, with the format also bound for the Cybertruck, Semi, and others.

Canoo also recently announced that Panasonic will supply 2170-format cylindrical cells for its upcoming vehicle.