eMobility technology – falling costs and increasing innovation
There are two main current EV battery technologies
- Battery electric vehicles (BEVs), which need to be plugged to be recharged
- Plug-in hybrid electric vehicles (PHEVs), which use a combination of battery power and liquid fuel
The cost of batteries for electric vehicles is falling markedly. For example, sales-weighted battery pack prices in 2019 averaged USD 156 per kilowatt-hour, down from more than USD 1 100/kWh in 2010.¹⁹ These cost reductions are expected to continue.
The average battery pack size across electric light-duty vehicles sold (including battery electric vehicles and plug-in hybrid electric vehicles) continues on an upwards trend; it is now 44 kWh, up from 37 kWh in 2018. Standard battery electric cars in most countries are in the 50-70 kWh range. This increase is driven, says the IEA, by two trends: battery electric vehicle models with longer ranges are becoming available and are increasingly in demand, and the share of battery electric vehicles relative to plug-in hybrid electric vehicles is rising. The most common cathode chemistry used in electric vehicle Li-ion batteries is NMC. Li-ion technology has made tremendous progress over the past decade in terms of energy density, costs and cycle life, but room for improvement remains.
The next generation of Li-ion battery technology, set to enter the market in the coming few years, are likely to have a low amount of nickel. The IEA says Li-ion batteries are likely to dominate the electric vehicle market for the next decade. From 2030, a number of potential technologies might be able to push the boundaries beyond the performance limits imposed by Li-ion battery technology.²⁰ However, there is no single technology that solves all the issues. And even once performance is proven in the lab, deployment and scale-up of new technologies will take time and have to compete with well-established Li-ion technology.
IRENA holds a similar view. It notes that some of the main challenges that EVs will have to face in the coming decades lie with their batteries.²¹ The years 2030 and 2050 may see breakthroughs in other battery technologies than lithium-ion and in their use for grid applications (see figure 3).
To address the challenges of electric mobility – such as power, distance travelled and charging time – new battery technologies are necessary, IRENA states.
Battery life-cycle challenges
The life-cycle of EV batteries is not without its challenges. There is still progress to be made in addressing the sourcing of raw materials, manufacturing emissions and the potential for a second life for batteries once their role in powering EVs is finished.
Here are some of the specifics that need to be tackled:
- Increase the energy density of batteries
- Scale up manufacturing facilities and increase throughput
- Increase energy efficiency and use low-carbon energy sources in mining and refining processes for raw materials, especially for aluminium, and in synthesis of active materials such as nickel, cobalt and graphite
- Increase energy efficiency and use low-carbon energy sources in cell manufacturing and pack assembly
- Ensure appropriate end-of-life battery management and build up processes for circularity
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There is also currently a lack of contract standardisation for the supply of these raw materials. It is anticipated that this will come in due course as demand for the raw material increases.
Any increase in mining capacity will need to be accompanied by a comprehensive risk management programme that considers issues such as conflict minerals, child labour, human rights and supply chain due diligence and management.
To date, there is very little specific legislation governing the sourcing of raw materials, but it is expected this will change as the market grows. The EU has already started to develop a common set of principles for a socially and environmentally sustainable mining sector in Europe. The OECD Guidelines for Multinational Enterprises and the OECD Due Diligence Guidance for Responsible Mineral Supply Chains are currently the main sources of reference for EU companies or those selling into the EU.
The UK, Germany, Belgium and the Netherlands encourage companies to implement the OECD Due Diligence Guidance for Responsible Supply Chains of Minerals from Conflict-Affected and High Risk Areas and the French Devoir de Vigilance requires companies to source raw materials in a socially and environmentally sustainable way.²² According to research from the National Grid in the UK, EV manufacturers are making big investments to give car batteries a new lease of life in large-scale battery storage systems.²³
Nissan is using retired EV batteries to provide back-up power to the Amsterdam Arena – the entertainment centre and home to Ajax Football Club.
Toyota will be installing ex-EV batteries outside convenience stores in Japan. The batteries will be used to store power generated from solar panels. The energy stored will then be used to support the power of drink fridges, food warmers and fresh food counters inside stores.
Renault has also announced that the EV batteries from the Renault Zoe EV will be repurposed to generate power to the Powervault – a home energy battery storage system. And Nissan has launched XStorage, using Nissan Leaf car batteries as storage systems for homes and businesses.
National Grid also notes that the current methods of smelting and leaching will be finessed in coming years, as will the battery designs to optimise the separation and recycling process of end-of-life batteries. In the UK, the Office for Zero Emission Vehicles (OZEV) has launched a £7 million competition for on-vehicle solutions that address challenges associated with the transition to zero emission vehicles, including improving sustainability.
The former Chief Technical Officer of Tesla has launched Redwood Materials, one of a crowd of new start-ups racing to solve a problem that does not exist yet; how to recycle electric car batteries that will be past their prime.
Source: IRENA