Advanced Research Projects Agency-Energy, or ARPA-E, an agency under Department of Energy has been researching latest battery technologies for years. The agency aim to outperform Tesla in battery technology.

Head of the agency Ellen Williams in an interview admitted Tesla achievement in battery technology, as she told Reuters, "What Musk has done that is creative and important is drive the learning curve. He's decided to take an existing, pretty powerful battery technology and start producing it on a very large scale."

"But it's not technology innovation in the sense of creating new ways of doing it. We are pretty well convinced that some of our technologies have the potential to be significantly better," she added.

ARPA-E was initiated in 2009 with initial budget of $400 million with target to invent the most cutting edge technologies for clean energy. President Obama has requested to increase budget for the agency to $1 billion for the next five years as the government planned to double its spending on research of clean energy. By 2021, U.S. government plan to boost its energy research and development budget to $12.8 billion.

"With that increased budget we can definitely make a difference," Williams said.

CNBC reported that ARPA-E get a huge boost after last year's United Nations Climate Change Conference (COP21) in Paris. In the conference, United States and 19 other countries are launching the Mission Innovation.

Mission Innovation is a global initiative to accelerate public and private clean energy innovation to address climate change. The initiative aimed to make clean energy affordable to consumers, and create green jobs and commercial opportunities. The initiative was announced by Bill during the conference.

According to Alveo Energy CEO Collin Wessells batteries are in the wild west phase. The San Fransisco-based startup, which were supported by ARPA-E, are working on development of high power, long lifecycle battery technology for renewable energy and microgrids. He also noted that huge manufacturing advanced will speed up the commercialization of battery products.

Speaking at the ARPA-E conference in Washington this week, Wessells said, "We are in a burst of innovation right now. Five years from now there will be a few technologies out there that nobody saw coming."

Meanwhile Tesla has already began mass-production of its Model 3 car. One main concern is the battery supply, but the company is confident about its world-largest battery factory, dubbed as Gigafactory in Nevada to supply the needs. Once fully operational in 2020, the facility will be able to produce 50 GWh annually to power up 500,000 Tesla car, as Motley Fool reported.

Tesla has already broken ground on the Gigafactory last year. While, ARPA-E is still on the laboratory testing with its battery technology, and still further away for public launched, moreover commercialization.