The electric vehicle (EV) revolution is speeding up, but it can only go so far without the necessary infrastructure and technology. As thinking shifts from fossil fuels to all-electric, visions of a brighter, more optimistic world come into view. The UK government’s pledge to ban the sale of all new non-electric cars, including gasoline, diesel and hybrid vehicles from 2035, highlights the drive to end the nation’s contribution to Climate Change by 2050.
If the 2035 target is to be met, we will all see evolutions in the transport and mobility routines that keep our lives moving. From using ultra-fast wireless charging to supporting the developing world by repurposing car batteries, WMG, at the University of Warwick, is delivering advances in electrification knowledge and technologies, which will enable the leap to an electric automotive future. So, for the now and the near future, what do we need to consider?
Making batteries better
Demand for EVs is surging in the UK and registrations of plug-in cars increased by more than 160,000 between 2013 and 2018. With the electrification industry estimated to be worth over £6bn (US$7.8bn) by 2025, the next decade presents a massive opportunity.
However, EVs will remain on the outskirts of mainstream until consumers are offered something that matches the model of usability, convenience and affordability that conventional vehicles offer today according to Professor David Greenwood. He is driving forward the £2m Innovate UK-funded Multi optimal Solutions for Energy Storage Systems (MoSESS) project in a consortium that is led by McLaren Automotive and includes project partner A123 Systems to reduce the size, weight and emissions of current EVs.
The vision is to improve all aspects of performance and reliability and unlock the possibility of producing a battery solution that matches the performance of conventional gasoline and diesel vehicles, meeting consumers’ expectations, helping drive the uptake of hybrid and electric transport and supporting the Government’s ‘Road to Zero’ strategy—aiming to make road transport emission-free by 2050. “The reason people don’t buy electric cars today is because they’re too expensive, there is widespread scepticism around the battery range and therefore pressing questions around the regularity and reliability of charge points. The current best-in-class technologies are able to meet the needs of a small percentage of users and the need to plan an efficient battery charging infrastructure is key,” explains Greenwood.
Current technology results in large EV batteries with long charging times. Even best-in-class energy densities mean that the battery needs to be comparatively large to achieve the desired electric range capability. Because they are large, they are also heavy, which means the vehicle consumes more energy in a journey. Then, for safety reasons, currently affordable traction batteries need to have a high level of complexity. So all in all you have a heavy, inefficient, cumbersome part.
“We aim to develop and integrate within a vehicle, a battery system based on a mixture of highly energy dense solid-state cells and high power density cells,” says Greenwood. “These new battery types are more efficient with better energy storage, a smaller package and the ability to fast charge. We want to deliver a solution with a simpler cooling system, a reduced dedicated crash structure for the battery, reduced charging time for up to 500km electric range, and a weight saving of up to 10% compared to existing solutions.”
Although efficiency, convenience and reassurance are vital factors for consumers, cost also remains front of mind in the decision making process for prospective EV adopters. WMG’s involvement in the Nextrode project, funded by The Faraday Institution, is tackling this. The project explores ways to make electrodes for Li-Ion batteries. Using WMG’s state-of-the-art battery scale up facility and the forthcoming UKBIC facility, the project allows WMG to model and optimise ways of driving down cost of manufacture for electrodes, increasing their energy storage capacity and reducing the time it takes to get to market.
The relationship between the charging infrastructure and the manufacture of the batteries is key, especially when considered in relation to consumers’ typical mobility behaviours and patterns. 98% of journeys are less than 50 miles, so carrying the load of a battery sized to deliver 300 miles on such short journeys somewhat counteracts the efforts to improve efficiency and usability for consumers. Considerations such as this show the importance of a robust battery charging infrastructure, and highlight that the technology has to respond to consumer lifestyles and patterns if it is to be successful on a mass scale. Professor Greenwood added: “With a reliable, accessible and ubiquitous fast charging network in place, passenger car batteries could shrink in size and cost to something which would deliver around 150 miles of real world range, halving the cost of the most expensive component in the vehicle.”
Developing a network: the right power in the right place
Although EVs have been on the market for some time now, the mass public uptake of the technology has not happened. Concerns about charging between journeys, as well as range anxiety are key barriers to buying an EV. Professor Richard McMahon from WMG explains: “Many buyers who have come early to EVs will probably be buying an electric car at the same time as having an internal combustion engine vehicle for longer distances. However, as electric cars become more widespread, drivers will want to travel greater distances hence the likely need for more public charging opportunities. Charging on motorways and along main roads is clearly an enabler of longer distance travel. The Tesla superchargers are one example; BP and National Grid amongst others are also looking at fast-charging centres. Solutions for on-street charging are also being developed.”
Start-up company char.gy has developed the technology to allow drivers to just plug their car into a lamppost. The company created a new EV charging point product, which can be easily installed onto existing lampposts. The installation requires no further power supply or any groundworks. WMG helped char.gy rapidly design, build and test a prototype of the new electronics board required for the design to meet EU standards for public charge points. The charge points are now ready for public use in London following char.gy’s integration within Transport for London’s (TfL) Charging Infrastructure Procurement Framework in 2018, which supports the roll-out of EVs by aiming to install over 1,000 on-street charge points by the end of 2020.
Helping individual vehicle owners charge their car is one thing, but the pressure is really on to come up with new solutions for the fleets of vehicles in our towns and cities which have no time to stop. Electric taxis are creeping into circulation but there is still an anxiety associated with charging. Are there enough charging points for enough drivers in a given city and does the EV battery last long enough to do enough jobs between charges? Drivers cannot afford to be stationary for long periods of time while they charge and the public in large cities expect there to be enough vehicles on the road to be able to hail a cab at any time.
Similarly, emergency vehicles are still predominantly diesel, and if a fleet is electrified it will need to guarantee an equivalent service level. It would be inconceivable for an emergency services vehicle have to wait to charge the battery.
This is where the wireless charging or ‘charge on the move’ idea comes in. McMahon comments: “The ‘charge on the move’ concept is really attractive in principle but there is more work to be done to ensure compatibility and to design installation procedures.” WMG and wider project partners are now working on a feasibility study to assess the potential for electric taxi wireless charging. The consortium can then apply for further Innovate UK funding for a large-scale commercial demonstrator project to test the technology and approach at locations within Nottingham and London.
Strengthening the UK electricity grid
Once the technology is perfected, though, it should be used efficiently, and this requires a distribution network that can cope with high levels of EV charging across a variety of neighbourhoods and locations. A truly sustainable system would be one where surplus energy storage capacity could be repurposed. This idea is being explored by another WMG research team, looking at the possibility of accessing the energy stored in EVs when they are not in use. This vehicle-to-grid (V2G) concept has the potential to address the imbalance, taking forward the idea of an energy connectivity landscape.
For the most part the public are in favour of EVs, but until they meet the threshold requirements of range, rechargeability and affordability of individual users, they will remain beyond reach
Project lead Professor James Marco thinks connecting EVs to the grid will provide a good solution to gaps in capacity, and modelling projects like this are helping to demonstrate the advantages of the system. He says: “We are using real-world data to demonstrate V2G. This not only helps to establish confidence in the technology, but also provides the invaluable learning that will be used to achieve the ultimate aim of making V2G an established component of the grid. Through proper management of the battery system, it is possible to mitigate battery degradation through V2G and possibly even extend battery life.”
After an EV battery has reached its expected lifespan of around eight to 12 years, and although the manufacturer is responsible for recycling the pack and must pay the costs associated with the transportation and processing, it is the final owner (normally an authorised treatment facility or scrap yard) that gets to define what should be done with the pack. They can sell it on for reuse or have it recycled.
However, batteries often retain up to 80% of their energy capacity and power after this automotive lifespan, meaning they could be suitable for ‘second-life’ applications, such as stationary energy storage for domestic and industrial use. The immediate priorities of driving cost down and streamlining manufacturing processes has led to battery designs which are increasingly difficult to reuse or recycle at the end of their life in a vehicle. Anwar Sattar, Lead Engineer in Battery Recycling at WMG, observes: “Many of the battery packs currently on the roads were not designed with end of life (EoL) in mind. The most important considerations for pack designers are cost, energy density, safety and ease of manufacture. This means that some battery packs will have a very low recyclability as they contain large amounts of material such as glue that makes them difficult to disassemble and recycle. Another major challenge is the lack of standardisation in design of the battery packs. This makes pack removal difficult as it varies from vehicle to vehicle.”
Having said that, work is underway to tackle this. WMG has been working with two global automotive suppliers focusing on how they can reuse and more efficiently recycle their batteries. Firstly, developing accurate and cost effective battery grading processes and secondly to help drive battery technology innovation that supports developing countries and isolated communities.
For the most part the public are in favour of EVs, but until they meet the threshold requirements of range, rechargeability and affordability of individual users, they will remain beyond reach. Great science and robust engineering can and will address these problems over time. WMG is working to make that a matter of years and not decades.
About the authors: David Greenwood is Professor of Advanced Propulsion Systems, James Marco is Professor of Systems Modelling and Simulation, Richard McMahon is Professor of Power Electronics and Dr Anwar Sattar is Lead Engineer in Battery Recycling at WMG, University of Warwick