Chris Kruger is passionate about safety, cost and performance and he has brought that enthusiasm to both his corporate and technical developments throughout his career. But it was a stroke of good fortune that led to a vital breakthrough.
He founded the marine battery manufacturer AYK Energy in 2018 with a very specific goal: to produce a low-cost battery that offered superior performance and safety while exceeding class and industry standards. He had good reason to be confident he could achieve his aims: he developed the very first marine type-approved battery in 2013 and he and his team can draw on his 15 years of industry experience.
That dates back to 2008 when Kruger – an electrical engineer by training – switched from working with semiconductors to focus on batteries because “I wanted to do something that helps the planet”, he said in an interview for this publication. He started with the automotive sector and led the team that developed the battery for the Fisker Karma, one of the world’s first production plug-in hybrid electric vehicles that sold mostly in the US.
But in 2010, even before that car went on sale in 2011-12, he had moved on to be Director of Engineering at Corvus, where he developed and installed the battery for the first hybrid propulsion ferry, Princess Benedikte, and the first fully-electric ferry, Ampere.
His next move, in 2015, took him to PBES as a founder and Chief Technical Officer, where he developed that company’s high-power battery, before leaving to set up AYK Energy.
This is where he was able to give his ideas about cost and concept free rein. “My feeling was always that marine batteries are just way too expensive”, he said, which could be tackled by taking production to China. That, however, was only part of the solution. By starting with a clean sheet without any legacy investment in established technology, he believed it was possible to design a third-generation battery quickly.
“We started by designing the battery management system (BMS) from the ground up”, he said. So, backed by venture capital funding, he and his team set out to design a battery – both its hardware and software – that would benefit from his experience of both design and installation work during his previous appointments.
“It was not easy going”, he said, but in 2020 “I had a piece of luck”. That came from making contact with battery cell maker EVE, which was keen to design a battery that could secure marine type-approval from class society DNV and had already devoted two years to the attempt.
After many conversations between the two organisations, Kruger’s counterpart at EVE laid down a challenge: “You say you can develop a type-approved battery, now prove it.”
Kruger set out to do just that: In exchange for space in EVE’s certified lab and the use of its test equipment, AYK would do the rest. Using EVE’s cells alongside AYK’s BMS, Kruger and his team designed, built and tested a marine type-approved battery in just six months, which was “quite a feat”, Kruger said. AYK paid for and sourced all the hardware and retained intellectual property in the final design.
Simple and safe
That design now forms the basis of AYK’s range of eight battery variants, all of them using the same battery technology and safety features.
Part of that safety design lies in AYK’s choice of cell chemistry. All its batteries use LFP – lithium-iron-phosphate – cells supplied by EVE, making the company unique in using that cell structure in all its products. It is cheaper than NMC – nickel, manganese, cobalt cells – which is the most common alternative battery chemistry, and will eventually be “the bridge chemistry to take us to the next generation of solid state batteries”, Kruger believes.
It is also safer, as demonstrated by China’s attitude towards them. That is where AYK’s batteries are made and the country will not allow NMC cells to be used for any application that involves transporting people.
LFP cells also operate at a lower temperature than NMC equivalents, so they do not need the same volume of cooling structures around them. This overcomes one difference between the two options: NMC cells have a greater energy density but once they are installed into batteries along with their cooling arrangements, their modular energy density is less than that of an LFP battery, Kruger pointed out. “We can fill most of the module with actual battery”, he said.
They are also less prone to thermal runaway and, should it happen, “it’s not a violent reaction that escalates very fast”, he said. In case that happens, AYK’s battery modules have an automatic water-based response system installed.
Water is used because it has a large phase-change energy value and in the event of a battery overheating, a sprinkler inside the module is activated. This will flood the affected module – not the entire bank of batteries – and because they operate at a low voltage of about 40V, electrical conduction through the water is not a hazard.
AYK has patented this arrangement in China and Kruger said that it exceeds class requirements for battery fire protection, which call only for a smoke detector in the battery compartment. In addition, AYK’s batteries have three smoke detectors within each module – two must activate before a response is initiated – and the modules are IP67-rated enclosures, each with a blow-out port to release any gasses that build up inside.
This is connected to an extraction duct with a fan to remove any flammable gasses from the battery to be vented outside while any water can be drained via a fitting on the duct piping.
Manufacturing upgrades
AYK will be increasing its manufacturing output from July in response to an order signed in January with Holland Shipyards Group to supply batteries for a zero-emission machinery retrofit on the container vessel, FPS Waal, operated by Future Proof Shipping.
Its diesel engines will be replaced with PEM fuel cells, storage for their hydrogen fuel, two AYK high density DNV-approved Aries 88 lithium batteries and an electric drive train. The order is the first time that AYK batteries will be used alongside fuel cells, making it a landmark contract for the company, Kruger said.
It will require increased production at its factory in Zhuhai, China, which will coincide with the opening of an automated manufacturing plant that will take over all its manufacturing, reducing production costs further.
This manufacturing model could also be replicated elsewhere in the world, should demand call for it. In the US, for example, The Jones Act encourages domestic sourcing for US-built ships, so if that market opens up, an automated production facility could be built to meet it.
In Europe, too, a similar plant could be built quickly. A site has already been identified and an automated production line could be operational just six months after construction begins, Kruger said.
He is proud of what he and his team at AYK have achieved in just a few years. “We have built the safest battery system with one of the highest energy densities in the industry”, he reflected. And its cost – already one of the lowest – “will go down because of manufacturing capabilities”, he predicted.
But he also stressed his batteries’ ease of installation and commissioning. “From the ground up, we designed our battery to allow remote access” which enables remote support during commissioning and remote software updates. Once installed, bugs and faults can be fixed remotely and data can be easily uploaded to The Cloud for storage and processing. “We believe we are the best and we will work very hard to remain the best”, he concluded.