(by John Roach, NBCNews) – Waiting hours for a cellphone to charge may become a thing of the past, thanks to an 18-year-old high-school student’s invention. She won a $50,000 prize Friday at an international science fair for creating an energy storage device that can be fully juiced in 20 to 30 seconds.

The fast-charging device is a so-called supercapacitor, a gizmo that can pack a lot of energy into a tiny space, charges quickly and holds its charge for a long time.

What’s more, it can last for 10,000 charge-recharge cycles, compared with 1,000 cycles for conventional rechargeable batteries, according to Eesha Khare of Saratoga, Calif.

“My cellphone battery always dies,” she told NBC News when asked what inspired her to work on the energy-storage technology. Supercapacitors also allowed her to focus on her interest in nanochemistry – “really working at the nanoscale to make significant advances in many different fields.”

To date, she has used the supercapacitor to power a light-emitting diode, or LED. The invention’s future is even brighter. She sees it fitting inside cellphones and the other portable electronic devices that are proliferating in today’s world, freeing people and their gadgets for a longer time from reliance on electrical outlets. [But in the future, the device could easily be used in roll-up phones or maybe even car batteries.]

“It is also flexible, so it can be used in rollup displays and clothing and fabric,” Khare added. “It has a lot of different applications and advantages over batteries in that sense.”

Khare’s invention won her the Intel Foundation Young Scientist Award at the Intel International Science and Engineering Fair, conducted this week in Phoenix, Ariz. 

[“With this money I will be able to pay for my college and also work on making scientific advancements,” Khare told the audience after receiving the prize.]

In announcing the winners of what it billed as the “world’s largest high school research competition,” Intel cited Khare for recognizing “the crucial need for energy-efficient storage devices” as the world rapidly adopts portable electronics.

The other winner of a Young Scientist Award with Khare was Henry Lin of Shreveport, Louisiana, who received a $50,000 prize for “simulating thousands of clusters of galaxies” to allow scientists to “better understand the mysteries of astrophysics: dark matter, dark energy and the balance of heating and cooling in the universe’s most massive objects,” the Intel statement said.

The top prize at the fair went to 19-year-old Ionut Budisteanu of Romania, who used “artificial intelligence to create a viable model for a low-cost, self-driving car,” according to an Intel statement. He received the Gordon E. Moore Award, named after the Intel co-founder, which includes a $75,000 prize.]

According to Intel, more than 1,500 young scientists from around the world were chosen to compete in last week’s fair.