SHANGHAI — The Chinese manufacturing giant CATL, the biggest supplier of batteries for the world’s electric cars, said Monday that it has made technological advances that would allow it to produce batteries that are cheaper, lighter, faster to recharge and more resistant to cold while providing greater driving range.

Most of the changes, which are a couple of years away from being widely available in new cars, could make electric cars more competitive in price and performance with gasoline-powered models.

CATL (Contemporary Amperex Technology Co. Ltd.) produces a third of the world’s electric car batteries and supplies 16 of the world’s biggest carmakers, including GM and the Shanghai factory of Tesla. Its main rivals for the global market are BYD in Shenzhen, China, which makes about one-sixth of the world’s EV batteries, almost entirely for its own cars; and Korean and Japanese battery manufacturers.

CATL executives spoke at a news conference before the Shanghai auto show, which starts Wednesday. The choreographed event evoked the launch of a new car model.

Batteries represent at least a third of the cost of an electric car, making CATL a critical player in the EV supply chain in China and beyond. Many automakers have been watching nervously whether CATL will someday try to establish its own car brand that could overshadow their models.

The biggest surprise by CATL was an announcement about auxiliary batteries for electric cars. The batteries would share space in the underbody of cars, where there is currently only one large battery.

The auxiliary battery would be the first commercially available electric vehicle battery that would not use graphite as one of its poles, CATL said.

Removing costly graphite will eventually make the batteries cheaper, after some initial costs, and will allow 60% more electricity to be squeezed in each cubic inch of the battery, said Gao Huan, CATL’s chief technology officer for electric cars in China. The extra energy density means that the car’s driving range can be greater, or the overall size of the battery can be reduced, leaving more room for the car’s passenger compartment.

The second battery also would provide backup in case one has trouble. That has become more important as self-driving features, which require uninterrupted electricity, become more common.

Ouyang Chuying, co-president for research and development at CATL, said auxiliary batteries without graphite would be available in cars in two to three years, possibly sooner. He declined to say which automakers might be the first to use them.

But taking out the graphite has a downside, which is why CATL will only remove it for the auxiliary batteries. Batteries without graphite recharge more slowly and cannot be recharged as many times.

The auxiliary batteries are meant to be used less frequently, on longer drives after the main battery is exhausted.

CATL, based in Ningde, also said its new system would allow an electric vehicle to be charged enough in five minutes to drive 320 miles.