(Yicai Global) Dec. 30 -- Shenzhen stock benchmarks reached their highest levels since 2015 on the last-but-one trading day of the year, with the lithium battery sector helping to power the advance.

The Shanghai Composite Index closed 1 percent higher at 3,414.45, while the Shenzhen Component Index added 1.7 percent to 14,201.57. The ChiNext, which tracks growth enterprises listed in Shenzhen, climbed 3.1 percent to 2,900.54.

The lithium batter sector gained an average of almost 7 percent. Contemporary Amperex Technology [SHE: 300750], the world’s biggest power battery maker, rose 10.4 percent to CNY340 (USD52) after earlier touching a record high CNY347.94.

CATL said earlier today that it plans to invest as much as CNY39 billion to build three new lithium battery plants in South China.

At more than CNY800 billion (USD122 billion), the firm’s market capitalization now puts it among the top 10 companies listed in the Chinese mainland.

Shares of power battery maker Farasis Energy [SHA: 688567] also gained more than 10 percent to CNY45.81 each.

Editor: Ben Armour