All-polymer batteries reduce costs by 90%, and the production process is as easy as buttering bread

Lithium-ion batteries are now the protagonists of the technological world. In our daily lives, from mobile phones and computers to the hot smart electric vehicles, lithium-ion batteries are indispensable to provide them with driving force. Hideaki Horie, who was the head of Nissan's electric technology development, has made an indelible contribution to the commercialization of lithium-ion batteries. Now, the all-polymer battery he developed can reduce the cost of mass production of batteries by 90% and greatly improve safety.

Horie Hideaki founded APB in 2018, a Tokyo-based company that aims to manufacture "all-polymer batteries," hence the name. Earlier this year, the company received funding from a group of Japanese companies, including Obayashi Corporation, industrial equipment maker Yokogawa Electric and carbon fiber maker Imperial Rayon.

Horie Hideaki said, "The problem with the current lithium battery production process is that the complexity of the entire manufacturing process is almost catching up with precision instruments such as semiconductors. Our goal is to simplify its manufacturing process and make it more like steel production."

The production of each battery cell needs to be carried out in dust-free conditions, with airlocks to control humidity, and constant air filtration and strict precision to prevent contamination of highly active materials. This series of operations is expensive  ,   so  much so that a  few top companies such as South Korea's LG Chem, China's CATL and Japan's Panasonic will spend billions of dollars to build a suitable battery factory.

The all-polymer battery developed by Hideaki Horie replaces the two basic components of traditional lithium-ion batteries - metal-lined electrodes and liquid electrolytes - with resin structures. This method greatly simplifies and speeds up manufacturing, and the entire production process is as simple as "buttering bread." 10-meter-long battery panels can be stacked on top of each other "like seat cushions." Importantly, resin batteries do not pose a risk of fire when punctured.

Bipolar structure all-polymer battery technology

The all-polymer battery (right) replaces the liquid electrolyte and metal electrodes in the traditional battery (left) with polymers. The front and back of each battery are composed of high-molecular polymer current collectors, and each has an electrode to form part of the single-cell battery shell. Stacking several such batteries together forms a battery pack with a bipolar structure, generating current perpendicular to the electrode plane.

Due to the bipolar structure and polymer component materials, fewer parts are required for battery manufacturing. Therefore, the all-polymer battery has high flexibility in battery size and shape, which will help us make thicker electrodes and larger batteries.

Takao Ando, ​​president and CEO of Sanyo Chemical, one of the largest investors in APB, said: "All-polymer batteries are not easy to catch fire, will not be damaged by drilling or cutting, have high flexibility in size and shape, and have low manufacturing costs. They will contribute to creating a sustainable society."

Focus on non-automotive sectors first

In March, APB raised 8 billion yen ($78 million), a modest sum by broad industry standards but enough to fully equip a factory to start mass production next year. Horie estimates the money could enable his factory to reach 1 gigawatt-hour of capacity by 2023.

Lithium-ion batteries have come a long way since they were first commercialized three decades ago. They last longer, are more powerful and cost 85% less than they did a decade ago, powering the growth of smartphones and tablets, which are increasingly powerful inside. But safety concerns persist, with batteries to blame for several fires in everything from Tesla cars to Boeing Dreamliners and Samsung phones.

"From a physics perspective, lithium-ion batteries are the best heaters ever created by humans," said Horie. In traditional batteries, a battery puncture generates a surge current of hundreds of amperes, several times the current used in ordinary households. The temperature will soar to 700 degrees Celsius. APB's battery avoids this catastrophic situation through a bipolar design, abandoning the current power bottleneck and allowing the entire surface of the battery to absorb current.

But the technology is not perfect, because polymers are not as conductive as metals, which may greatly affect the battery's carrying capacity. One disadvantage of the bipolar design is that each battery can only be connected in series back-to-back, making it more difficult to control a single battery. The cost reduction is not enough to compete with existing lithium-ion batteries. In the next 15 years or even longer, lithium-ion batteries with liquid electrolytes will still be the mainstream, although they are not perfect and are very expensive.

Horie also admitted that APB cannot compete with battery giants, as the latter have invested billions and benefited from economies of scale. Therefore, APB will not target the "red ocean" in the automotive field, but will first focus on buildings, offices and power plants. By 2025, the battery market will be worth $100 billion worldwide, more than five times the size of last year. The United States and China alone may grow 10 times to $7 billion during this period, becoming the main source of growth in energy storage demand.

Hideaki Horie's battery career 

Horie, 63, began his career at the dawn of lithium-ion batteries. Early in his tenure at Nissan in February 1990, he began research on electric and hybrid vehicles. A few weeks later, Sony announced plans to commercialize lithium-ion batteries, shocking the industry that had bet on nickel-metal hydride technology. Horie saw the promise and pushed the two companies to jointly conduct research that same year.

In 2000, when Nissan decided to abandon the battery business, Hideaki Horie successfully persuaded Ghosn to invest in the electric vehicle field, which led to the Nissan Leaf, which dominated the electric vehicle field for 10 years. Hideaki Horie proposed the idea of ​​all-polymer batteries when he was working at Nissan, but failed to get the support of the company and could not be realized. In 2012, when he was teaching at the University of Tokyo, Sanyo Chemical Industry Co., Ltd. found him and jointly developed the world's first battery using conductive gel polymer. In 2018, Hideaki Horie founded APB, and Sanyo Chemical became one of his early investors.

Horie said APB has already secured its first customer, a large Japanese company whose products are mainly sold overseas, and that specific details will be announced as early as August this year. "This proves that our batteries can be mass-produced," Horie said. "We are making chemistry the protagonist again, and battery manufacturers will only be assemblers."