Cambridge start-up AC Biode creates world's first AC battery

A Cambridge start-up is seeking £400,000 in seed funding to develop its revolutionary battery to power electric cars and drones.

AC Biode has created the world’s first standalone alternating current (AC) battery using something it calls a ‘biode’, which has both the characteristics of an anode and a cathode. The company says the AC battery is more efficient, safer and about 30 per cent more compact than regular batteries, which use direct current (DC).

Tadashi Kubo, CEO and co-founder, told the Cambridge Independent that he aims to work with the Cavendish Laboratory in Cambridge to deploy Nobel Prize-winning electrical circuit technology invented there in the 1930s with the new battery.

“We are going to use existing materials and production lines but switch from DC to AC. All the batteries in the world are direct current,” said Tadashi. “At the moment when you charge a battery, the power source comes from AC and the battery is DC. The majority of motors, such as in electric cars or drones, are AC. So you lose up to 35 per cent of electricity. We can reduce the loss.”

In DC, the current flows in one direction, while in AC, which is used for the mains supply in our homes, it changes direction many times a second. As batteries have a positively charged electrode, or anode, and a negatively charged one, or cathode, they have traditionally suited DC.

“We developed a biode – a word we created – that can be anode and cathode depending on the current. When we turn on the switch, we put on the battery and the biode and anode will be interacting through electrons. When the switch is off, the biode and cathode will be interacting,” explains Tadashi, who launched the business with his co-founder while completing an MBA at the Cambridge Judge Business School.

“We can have a standalone, alternating current battery, which is more compact and it is safer because the voltage will be divided by the biode. The difference of each electrode will be two volts instead of four volts.

“It is mainly for big applications –electric cars, drones, electric aeroplanes and energy storage for renewable energy. In the future, we want to put it in ships and forklifts.

“The capital expenditure will be 20 per cent more expensive, for the moment, but the impact of capex will be minimised for big applications.

“We have a dozen watt prototype, but we need to raise £400,000 seed funding to scale it up to a few kilowatts, which is sufficient for electric cars and drones. So we are raising funding in Cambridge and Japan.”

AC Biode is seeking angel investment to develop its patent-pending technology, and is also applying for funding from Innovate UK, the Japanese government and the European Union’s Horizon 2020 fund.

The demand for more efficient batteries is growing as the market for electric vehicles, aeroplanes and drones grows. Market research firm MarketsandMarkets puts the world market cap for mobility batteries $17billion by 2021.

This has driven ongoing efforts to develop and manufacture solid-state batteries, using solid electrodes and solid electrolytes, as an alternative to conventional lithium-ion batteries.

But Tadashi said: “When we develop new materials, such as the all-solid state battery, it takes more than five years and you need need to invest a tremendous amount of money – probably dozens of millions of pounds.”

The ability to adapt existing infrastructure offers AC Biode a compelling advantage.

It won the IMAGINE IF! start-up competition at UCL in London and was one of 15 UK companies to make the final 150 in the European Startup Prize for Mobility, a Europe-wide competition co-founded by the EU Parliament and aimed at those developing sustainable mobility solutions.

Meanwhile, conversations have begun with the Cavendish Laboratory to utilise its special electric circuit called the Cockcroft-Walton generator. The circuit generates a high DC voltage from a low-voltage AC or pulsing DC input.

Cavendish physicists John Cockcroft and Ernest Walton created it and used their design in 1932 to power their particle accelerator, which performed the first artificial nuclear disintegration. They won the 1951 Nobel Prize in Physics for ‘Transmutation of atomic nuclei by artificially accelerated atomic particles’.

The circuit is still used today in particle accelerators, but also in electronic devices that require high voltages, such as X-ray machines, TV sets, microwave ovens and photocopiers.

Tadashi, who was born in Nagasaki but grew up in Tokyo, says: “This electric circuit boosts voltage very efficiently but no-one else in the world has utilised it for mobility applications yet. It is mainly used for particle accelerators, which my engineer has specialised in.

“We want to co-develop this technology with the Cavendish Laboratory. We have started conversations.

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“We need to develop the electrical circuit but also optimise the biode and the switch structure of the battery. Even though we are going to use the existing battery and production lines, we need to modify and optimise the structure and work out how to manufacture it effectively.”

In the longer term, they also aim to take their technology into AC storage for off-grid areas and even space applications.

AC Biode is currently a team of three. Tadashi, who divides his time between Cambridge and Japan, spent 12 years at Sojitz Corporation on business development and project finance in the battery, machinery, infrastructure and renewable energy markets, mainly in Africa and Latin America. He has worked in Asia, Angola and Brazil.

His co-founder and CTO is Dr Atsushi Mizusawa, who has spent 25 years in the field of batteries and circuits. The company’s third member is engineer Imen Jarrahi, based in Kyoto, Japan, who has previously worked on the quality control of machinery.

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