The more time people spend on their smartphones, the faster their handsets run out of batteries. To solve this "battery anxiety", Chinese companies are working on cutting-edge flash-charging technologies to bring smartphones back to life as soon as possible.

Smartphone maker Oppo has unveiled its 125W Flash Charge technology, which the company said can charge a 4,000mAh battery up to 41 percent in just five minutes and fully charge it in 20 minutes.

Despite the fast charging speeds, Oppo said its new technology wouldn't impact the battery as its life expectancy had been maintained at 80 percent after 800 charging-discharging cycles.

To better protect the battery, the company has also designed a customized intelligent chip, 10 new temperature sensors and a 128-bit encryption algorithm to deliver a fast, safe charge. As a result, these new additions maintain body temperature of devices under 40 degrees Celsius during the charging process, Oppo said.

The new technology is an evolution of Oppo's existing SuperVOOC and VOOC architectures. The smartphone maker has developed a string of customized chips to enable faster charging.