Qichao Hu believes he’s on the cusp of one of the most highly anticipated developments in industry: the next battery revolution.

As founder and CEO of SolidEnergy Systems, a startup based in Woburn, Massachusetts, he’s come as close as anyone to commercializing rechargeable batteries made of lithium metal. These promise twice the energy density of lithium-ion batteries, the current industry standard for nearly all electronics and electric vehicles.

Since the development of the lead-acid battery in 1870, there have been only five major breakthroughs in battery technology—with energy density doubling roughly every 30 years. If the pattern holds, the next breakthrough is almost due: lithium-ion batteries, whose anodes are usually made of graphite or silicon, were first commercialized in 1991 by Sony.

The boost in energy density offered by lithium metal batteries could effectively double the range of an electric vehicle. The problem is that lithium metal is highly reactive. When charging, early prototypes of lithium metal batteries would form needle--like structures known as dendrites, which could short the cells and cause them to catch fire or explode.

Hu, who was born in China and moved to New York at 12, developed a liquid electrolyte, consisting of a high--concentration solvent in salt, which reduced the formation of dendrites. Building on this solution, SolidEnergy Systems developed a pilot line of lithium metal batteries in 2016 that are now being tested in drones. Later in 2019, it will open the world’s largest manufacturing facility for lithium metal batteries in Shanghai, where Hu hopes to scale up production to tens of thousands of cells per month.