Amprius is combining with the transportation-focused SPAC Kensington Capital Acquisition Corp. IV in a deal that was unveiled Thursday.

Several other companies, including silicon-anode battery firm

Enovix Corp.

, are working to mass produce batteries that can store more energy and power electric vehicles further between charges, advancements that analysts say could make them more mainstream and reduce the world’s reliance on fossil fuels.

Amprius says it is unique because it has been selling products commercially since 2018, has a patented design to make anodes completely out of silicon and makes batteries strong enough to power electric aircraft, which haven’t received as much attention from battery makers.

“We believe this will be a mainstream technology,”

Kang Sun,

CEO of Amprius, said in an interview. He said the company hopes to use the money from the deal to scale its manufacturing capacity and meet demand.

Founded in 2008, Amprius joins many other clean-energy startups in reaching a SPAC deal to go public.

Also called a blank-check firm, a SPAC is a shell company that raises money and trades on a stock exchange with the intent of combining with a private firm to take it public. After a deal is reached and approved by regulators, the company going public replaces the SPAC in the stock market. Such mergers have become popular alternatives to traditional initial public offerings in the past few years, allowing companies to raise cash while accessing individual investors.

Many startups that recently went public have hit technological roadblocks and have been hurt by global supply-chain disruptions, sending share prices tumbling and slowing the pace of new activity so far this year.

Some companies that previously announced SPAC deals have terminated their combinations. The market for traditional IPOs has also cooled, hurt by a broader stock-market selloff driven by worries about high inflation and rising interest rates. Fast-growing, unprofitable startups have been among the hardest hit.

Justin Mirro,

the SPAC’s CEO, said he is confident in the merger because of its unique structure and the SPAC team’s experience previously taking public solid-state battery startup

QuantumScape Corp.

and electric-vehicle charging company

Wallbox

NV.

As part of the deal, Amprius plans to raise $200 million in equity from investors. That money and the $230 million the Kensington SPAC raised in March could be used to expand the business, though SPAC investors can pull out their money before a deal goes through. Low share prices typically prompt such withdrawals.

To minimize withdrawals and motivate investors to keep their money in the deal, the Kensington SPAC gives investors an extra warrant allowing them to buy additional shares at a specific price in the future.

Write to Amrith Ramkumar at amrith.ramkumar@wsj.com