OOPS: China’s booming electric vehicle market is about to run into a mountain of battery waste.

The average lifespan of a lithium-iron phosphate (LFP) battery, the dominant type in China’s electric vehicles, is around five years, according to Li Changdong, chairman of the Hunan-based Brunp group, China’s top electric car battery recycler in 2016 (link in Chinese). Most batteries installed on electric vehicles during the 2012 to 2014 period will be retired on a large scale (link in Chinese) around 2018, Li told the Beijing-based newspaper Economic Information Daily.

In 2020, nearly 250,000 metric tons (276,000 tons) of batteries, or 35 gigawatt-hours of batteries, are set to be retired—nearly 20 times those depleted in 2016, GaoGong Industry Institute, a Shenzhen-based electric car industry research firm, told Quartz.

The battery is the heart of the electric vehicle industry, and the country needs a well-established battery recycling system, Xin Guobin, a top industry and tech official, told a national forum for the battery-powered engine industry Tuesday (link in Chinese) (Sept. 26). But recycling these batteries isn’t easy, due to the sophisticated chemical procedures involved. If it’s not done properly the heavy metal contained in the battery can lead to contamination of soil and water.

Unexpectedly.