Xiaomi Corp, the Chinese smartphone vendor that overtook Apple Inc and Samsung Electronics Co in the world's largest market, now faces another foe: Counterfeiters.

Sales of the company's Mi Power Bank battery pack for smartphones hit 14.6 million units last year, less than half what the total should have been, said Chief Executive Officer Lei Jun.

"What is the biggest problem? There are many fakes," Lei said. "If there were no counterfeits, our sales would be double or triple. The product has been recognized by everyone."