Cambridge team forges new lithium-ion battery production methodology

A team of Cambridge engineers and researchers, having developed a next-generation lithium ion battery using flame spray pyrolysis (FSP), has now embarked on the road to commercialisation.

The new technology has been developed by Cambridge researchers Professor Simone Hochgreb, Dr Adam Boies and Professor Michaël De Volder working alongside Professor Kai Luo from University College, London (UCL).

The science focuses on production techniques for enhanced materials for electrodes, especially the cathode (positive electrode) used in lithium-ion batteries. Progress is required to meet the power density and cost requirements for the next-generation EVs and energy storage systems.

Mainstream automotive companies favour nickel manganese cobalt oxides (NMCs) with various metal contents and surface features, due to the high number of charge and discharge cycles the NMC battery can withstand.

FSP is a new method used to produce a wide variety of functional materials in the form of powders (nanoparticles) and in large quantities. It is an effective and scalable industrial process that is easy to handle and one that maintains excellent product quality.

New research and production techniques including FSP will be explored in new research funded by the Engineering and Physical Sciences Research Council, a British Research Council organisation whose grant is for £388k. The project is titled ‘Mechanisms and Synthesis of Materials for Next-Generation Lithium Batteries Using Flame Spray Pyrolysis’. Commercial partners are Contemporary Amperex Technology Co, Echion Technologies, PV3 Technologies and Shanghai Tang Feng Energy Technology.

Prof Hochgreb, of the Department of Engineering at the University of Cambridge, said: “The long-term outlook for electric vehicles – EVs – is strong, with the electrification of the transport sector considered a natural development in order to make use of energy from a wide variety of sources, and to reduce CO2 emissions and combat urban air pollution.

“One of the biggest obstacles facing us in making the transition to EVs is the charging infrastructure itself, which is why research is needed to ensure that the power density and cost requirements for next-generation EVs and energy storage systems are met.

“Our manufacturing technique for lithium-ion batteries using FSP is a one-step continuous process with the potential to produce designer materials at scale and low cost.”

The high-performance cathode materials for lithium-ion batteries are based on layered, multi-element metal oxides and carbon-metal oxides, with inherent potential for high-speed continuous processing – and, eventually, mass production.

The work, however, is at an early stage, says Jean De La Verpilliere, CEO and co-founder of EchionTechnologies, who told the Cambridge Independent: “Cambridge University and UCL are doing world-leading research on next-generation battery technologies, and we are very pleased to support them by providing our views on industry requirements to enable commercialisation.

“Grants like this one are a great opportunity to bridge the gap between academia and industry, which will benefit both Echion and the scientific community at large.”

The commercial partners “are at arm’s length”, notes Prof Hochgreb, as “they are not contributing significant funds, only in kind advice”. The real work will be done by the University of Cambridge and UCL.

Prof Hochgreb adds: “We will be doing the experiments at Cambridge, building a reactor that can produce carbon-coated NMC oxide aerosols; these will then be sampled, collected and tested for their electrochemical properties in battery cells.

“The overall aim is both to understand what is the sweet spot of particle size, as well as to understand the process by which the NMCs might be made in a single continuous process in a flame-driven furnace.

“The funds go to pay for 36 post-docs at Cambridge, with a computational counterpart at UCL.”

Steve Thomas, associate director - applied science at Cambridge Consultants, says that improved battery performance is an important step among many that will be required to save the biosphere.

“FSP is definitely an interesting synthesis method for the controlled production of metal oxide nanoparticles,” Steve says. “It is particularly relevant for cathode materials for lithium battery production because the surface area and microstructure of the material contribute heavily to the performance and lifetime of the battery.

“As well as being scientifically interesting for controlling properties, it could also provide a lower cost method for producing cathode materials – a research group at the University of Missouri recently published an analysis suggesting that FSP could reduce the minimum selling price of NMC cathode materials by more than 15 per cent. Since cathode materials currently account for around 30 per cent of the cost of large battery cells, this could lead to useful cost reductions.”

The immediate problem to the wholesale adoption of electric vehicles, however, is not the science, it’s the infrastructure.

“Subtle improvements in battery specific power from FSP as a manufacturing technology may mean that the same cars have a more comfortable distance between charging points, but it is unlikely to solve the far more significant challenges that our electricity supply faces if we are to replace all our motor vehicles with EVs any time soon,” Steve concludes.