Science and Technology Group

FAQ

Next Meeting: Prof David Howey, Batteries and Beyond

25th April, 2018

The planet's electric supply grids have been described as "the world's largest supply chains to operate without the benefit of warehouses". With fossil fuel generation, because the chemical energy in coal, oil or gas could be stored at negligible cost until it was needed, storage of electrical energy was not important. Now, much of our electricity is being produced from the energy of wind, sunlight and the tides. Energy from these sources cannot be stored so if it is not to be wasted we will need to have a way of storing it. The alternative is to have the huge capital cost of a backup network fossil fuel stations, something which would seriously damage the economics of renewable generation to which this country is committed under the Paris Climate Accord.

Without better batteries, owners of electric cars will forever suffer from 'range anxiety'. Having one's phone go flat is bad enough, just imagine being stranded miles from the nearest charge point, without the option of getting a lift to a filling station for a can of petrol. Sadly, Moore's Law does not apply to batteries, and a lead-acid accumulator has much the same capacity (and weight) as it did 160 years ago, when it was invented.

Battery technologies have have improved, but this improvement always lags the increasing demands on batteries in a way that threatens the game-changing technologies of the future. Our speaker will talk about whether this lagging performance will persist and delay the much needed advances, or whether the huge resources devoted to improving battery technology over the last few decades at last pay off.

Further Reading

• Lithium-air batteries

• the utility death spiral

• Overcapacity in the market for batteries

• Solid-state batteries

• vanadium redox battery

• zinc-bromine battery

• sodium sulfur battery

• molten salt / liquid metal batteries

• organic redox batteries

David Howey is an Associate Professor in Engineering Science and a Tutorial Fellow at St Hilda’s College Oxford. His team's primary interest is in the modelling and management of electrochemical energy storage devices for automotive applications such as electric and hybrid vehicles, and also grid and off-grid power systems. The group develops novel instrumentation, diagnostics and modelling approaches that enable operation closer to performance limits, which is essential in order for these systems to reach commercial viability and make a positive impact on society and the environment.

Prof Howey's lab includes a range of battery test equipment, thermal imaging and calorimetry, data acquisation, scopes, 4Q power supply/loads, a dSpace battery simulator, and a 3D printer. Some examples of work include:

• Improved modelling of battery open circuit voltage (OCV) for battery management systems.
• A system for measuring electrochemical impedance using existing power electronics to excite a battery - this can be used for temperature estimation in cells amongst other things.
• Development of advanced battery management systems (BMS) that use electrochemical models for state estimation (also relevant for supercapacitors)
• Modular BMS/power electronics/battery systems that enable matching different types of cells together to get the most out of each of them.
• A novel electrical system for measurement of convective heat transfer in motors.

Prof Howey studied engineering specialising in electrical and information sciences at Queens’ College, Cambridge University. After working as an engineering consultant, he undertook a PhD at Imperial College London on the subject of thermal design of electrical machines. Subsequently he worked as a post-doctoral researcher at Imperial on two automotive projects investigating electrically assisted turbocharging and advanced battery condition monitoring before being appointed at Oxford in 2011 where he heads up the Howey Research Group.

Prof Howey states:

The main focus of our research is energy storage systems for automotive, grid, and off-grid applications. We also have a small secondary focus on electrical machines. You can find out more about our specific themes by clicking through the pictures below. Lithium-ion batteries are a key area, but we also investigate lead-acid and sodium-ion batteries, supercapacitors, flow batteries, and fuel cells. We collaborate widely with industry; many of our partners are at the bottom of this website.

There are many interesting challenges for the large-scale uptake of electrochemical energy storage including system integration, degradation, thermal management and dynamic modelling. Operating devices outside safe limits of temperature, voltage and current may lead to catastrophic failure. Moreover, integration into higher-level vehicle and grid environments is challenging because properties of interest such as state of charge and state of health are not directly measurable. Performance also deteriorates as a result of various degradation mechanisms and the complexity and interactions of these mechanisms make it difficult to predict decreases in battery capacity and power capabilities accurately.

Month	Day of Month	Speaker	Title
February	21st	Dr James Luke	Recent Developments in Artificial Intelligence
March	14th	Mr Simon Wright	Gene Editing and Intellectual Property Law
April	25th	Prof David Howey	Energy storage technologies - batteries and beyond
May	23rd	Dr Mohammed Al-Ubaydli	Patient-Centred Medicine
June	12th	Dr Vinton G Cerf	Google and the Internet
September	18th	Mr Romain Kidd	3D Printing
October	15th	Prof Paul Newman	Mobile Autonomy
October	28th	Dr Gary McLean	Towards a Vaccine for the Common Cold

2019 Programme

Provisional dates for 2019 are as follows:

Month	Day of Month	Speaker	Title
January	23rd
February	27th
March	27th
April	24th
May	29th
June	26th
September	18th
October	23rd
November	27th