All-solid-state batteries will be launched on the market within 6 years

At 1:00 p.m. Beijing time on April 8, 2022, Nissan held an online briefing on all-solid-state battery technology.

On November 29 last year, Nissan Motor CEO Makoto Uchida and Chief Operating Officer Ashwani Gupta released the "Nissan Ambition 2030" through an online live broadcast.

It mentioned that Nissan was one of the first companies to independently develop automotive lithium-ion battery technology and has been exploring it for 30 years. On this basis, it will introduce cobalt-free technology. The goal is to reduce the cost of liquid lithium-ion batteries by more than 65% compared to the second-generation Nissan LEAF by 2028.

Batteries are the key to transformation. Nissan is researching solid-state battery technology (ASSB). By fiscal 2026, it plans to invest 140 billion yen (about 7.9 billion yuan) and cooperate with global partners. By fiscal 2028, it will launch electric vehicles equipped with this battery technology. In fiscal 2024, it will build a pilot plant in Yokohama, Japan.

Kazuhiro Doi, Nissan Motor's vice president for advanced battery research, wants to dispel the assumption that solid-state batteries are safer than today's lithium-ion batteries.

True, next-generation solid-state batteries ditch flammable liquid electrolytes. But they cram more energy in, and if things go wrong, they could cause violent sparks.

Kazuhiro Doi, who leads Nissan's solid-state battery development efforts, warned that solid-state batteries have twice the energy density of current lithium-ion batteries and are therefore a more dangerous potential bomb. "If a major accident occurs, solid-state batteries could be more catastrophic than current batteries."

However, Kazuhiro Doi is also convinced that Nissan can currently overcome such safety issues and other key factors that make solid-state batteries difficult to achieve.

Kazuhiro Doi's team has been working hard to solve these problems. Nissan Motor has promised to bring lighter, smaller and more energy-dense solid-state batteries to market in just six years.

Nissan believes it can achieve a battery that has twice the energy capacity of lithium-ion batteries and charges in one-third the time.

All-solid-state battery technology can effectively reduce battery costs. Nissan plans to reduce battery pack costs to $75 per kilowatt-hour by fiscal 2028. In the future, the cost will be further reduced to $65 per kilowatt-hour to achieve cost parity between electric and fuel vehicles.

The automaker hopes such breakthroughs will help it launch electric models in a range of new segments, such as pickup trucks, large SUVs and even sports cars, where weight and size are an issue.

"I think all-solid-state batteries can be a game changer," said Kazuhiro Doi.

Manual trial production

Nissan has only taken the first step toward this goal, setting up a feasibility study laboratory to conduct hand-made, limited-volume production experiments on the battery. If all goes according to plan, the small, secret factory will start a pilot in 2024 and achieve large-scale mass production in 2028.

As Nissan grapples with this important new technology, companies from Toyota Motor Corp. to Volkswagen AG and General Motors Co., as well as a host of startups and nearly all of their traditional rivals, are racing to find the right path to success in the field.

A peek into Nissan's labs shows how long and difficult the road to solid-state batteries will be.

The 1,400-square-foot workshop, an enclosed dry room inside an old warehouse at Nissan's Oppama plant, is where engineers prototype new catalysts.

In the dry room, about 10 workers laboriously mix electrolyte slurry, scooping cathode powder from plastic cups with long spoons, a process done entirely manually. They blend it into an inky black goo and spread it like pancakes onto thin aluminum sheets—only two cells at a time.

After the goo dries, the thin aluminum sheets go through a phone booth-like stamping machine that uses three times the pressure of a standard lithium-ion battery.

Workers then cut the electrolyte sheets into the right size and carefully stacked them with the anode sheets. Finally, they vacuum-sealed the four-layer battery into an aluminum foil bag.

The work is laborious and time-consuming. Most of the process is done in a plexiglass glove box to maintain ultra-low humidity and cleanliness. Because the room is so dry, technicians need to take a break every two hours to rehydrate.

50 per month

Currently, the lab can produce only about 50 of these four-layer cells per month, said Kenzo Oshihara, Nissan's deputy general manager in charge of innovative battery production processes.

Oshihara estimates that an electric car would need about 5,000 of these cells.

“It will take a long time to make batteries for cars in this pilot room. Equipment for mass production must be more sophisticated,” Oshihara added.

The bigger challenge lies in technology and manufacturing. Currently, Nissan is still looking for the right chemical materials for the cathode and anode. The company has a partnership with NASA to search for effective material combinations in NASA's huge battery database.

Using AI screening methods, Nissan believes it can cut research time by more than half, from five to 20 years to two to three years.

Nissan is also focusing on cobalt-free cathode chemistries, possibly using sulfur or manganese because those materials are relatively abundant and inexpensive, Doi said. For the anode, Nissan is considering silicon-based or lithium metal compounds.

Precision above all else

The next step is to manufacture these batteries to strict standards.

First, the slurry must be finely blended and all lumps must be cleared out to maximize the battery's conductivity. The cathode-electrolyte-anode layers need to be arranged with absolute precision. Along the way, Nissan must perfect how to bring all of these procedures to mass production.

“It’s all about precision, but precision is related to cost and speed,” Doi said. “It’s a much more complicated process than with conventional lithium-ion batteries.”

Nissan says it has overcome some hurdles.

The cathode uses a binder that reduces resistance and improves the movement of lithium ions. Engineers also found a material that inhibits the formation of dendrites, which can cause batteries to short-circuit. They also invented a design that allows the electrolyte and electrode layers to repeatedly expand and contract without separating.

What’s more, the team says they’ve cracked the secret to fast charging at low temperatures.

Independent research and development

Although a growing number of startups and suppliers are trying to enter the solid-state battery field, Nissan believes that going it alone and conducting independent research and development has more advantages than cooperating, at least in the early stages.

“They don’t have mature technology to work with automakers like us,” Doi said of outside suppliers. Nissan wants to control know-how in areas such as battery design and manufacturing, not necessarily the chemistry of the raw materials themselves.

"This will be the source of our competitiveness," he said.

But Nissan has only a few years to fix the problem and hit its cost target by 2028. The company hopes to do so by using cheaper materials and streamlining the production process.

"Of course, we are currently talking about the R&D process, so we are not 100% confident. But as long as we work hard, we can do it," said Kazuhiro Doi.