Progress Towards Fast Charging for Electric Vehicles
Earlier this year both the UK and French governments announced plans to phase out sales of new petrol and diesel vehicles by 2040, providing more evidence of the shift towards electrification. Every manufacturer is busy developing the next generation of electric cars and solutions to some long-standing problems are on the verge of being realised.
The key issues for electric vehicles have always been driving range and charging infrastructure. Tesla was the first manufacturer of EV’s to tackle the problems by building its own network of superchargers - providing 80% of charge within 30 minutes, and 170 miles range - but the Combined Charging System (CCS) and CHAdeMO charging standards have otherwise competed to be the universal charging standard. This creates a problem of compatibility which is yet to be fully resolved.
Both standards are working towards 150 kW charging with a future view to 350 kW in order to reduce charge time, whilst developing a charging infrastructure across Europe and the US. Several manufacturers have produced vehicles able to accept a charge of up to 100 kW, and Porsche has continued to press ahead with its Mission E concept which would charge at 350 kW via an 800v charging system. We are also beginning to see various innovations in battery technology and charging adaptors, and it is clear that the electric evolution is gathering pace.
Fast Charging Networks
CCS is the most common charging standard in Europe, while CHAdeMO has been the mainstay of Japanese automakers, including Nissan. Some charging stations are compatible with both standards to suit drivers of cars adhering to either protocol, but if one is to win out in the long run it is likely to be CCS. It has been adopted by SAE as the Fast Charging Standard to be developed, and Tesla becoming a member of CharIN e.V. in 2016 could be pivotal.
CharIN is a consortium of automakers that works towards the development of a fast charging network in Europe with the aim of 150 kW charging. Tesla had famously invited other automakers to use its supercharger protocol, and this collaboration suggests that Tesla has chosen which universal standard it will seek to be compatible with. That could be pivotal in the future because of Tesla’s plans for the model 3 to become the most popular electric car within 12 to 18 months - the latest target for production volume of 5,000 cars per week is March 2018. Although the model 3 still uses Tesla’s supercharger system, future vehicles could be CCS compatible and charging networks will seek to support the most popular electric cars.
Moving ahead with developing the charging network in Europe, CharIN recently announced a joint plan between members CLEVER and E.ON to establish a network of 180 ultra-fast charging stations across seven countries, connecting Norway and Italy. The project has received €10 million in funding from the European Commission’s Connecting Europe Facility program (CEF) and will see charging stations located every 120-180 km along motorways. Each site will offer 150 kW charging with the potential to upgrade to 350 kW in the future. THe stations, located throughout Germany, Denmark, UK, Italy, Norway, Sweden and France will enable charging of a 400 km range battery in 20-30 minutes.
The consortium also announced the NEXT-E Project which will build a further network of 252 fast charging stations in the Czech Republic, Slovakia, Hungary, Slovenia, Croatia, and Romania. The project received €18.8 million in funding from the CEF and will build 222 fast charging stations with charging power of 50 kW, and 30 ultra-fast charging stations with power of 150 - 350 kW, with work scheduled for 2018 to 2020.
Porsche Mission E
Porsche made the headlines with the Mission E concept when it claimed its 800v charging system could charge the Mission E’s battery to 80% within 15 minutes. Porsche also said it had the backend to support 350 kW charging, and earlier this year the carmaker unveiled its first two 350 kW chargers. The production vehicle is not due for launch until 2019 but Porsche has installed the two chargers at its new location in Berlin-Adlershof. The units use the CCS charging standard and can currently charge at 50 - 150 KW until vehicles can support higher charge rates.
ABB Terra HP
Another step towards ultra-fast charging in Europe can be seen in ABB’s recent announcement of its first 150 - 350 kW product with the new Terra HP High Power Charge system, unveiled in October at EVS30 in Stuttgart.
The Terra HP charging system has the capacity to charge both 400v and 800v cars at full power. The 375A output single power cabinet can charge a 400v car at full 150 kW continuously. ABB’s Dynamic DC power sharing technology allows a two-power cabinet charging system to charge two cars simultaneously, with up to 350 kW and 500A, while optimizing the available grid connection and power delivery to the two vehicles.
The system has already been proven in commercial electric bus field installations and benefits from ABB’s Ability Connected Services, designed to deliver enhanced functionality for charging operators to minimize downtime and reduce costs.
An innovative approach to non-standardized charging infrastructure came from automotive supplier Continental earlier this year with its AllCharge technology. The system is designed to turn the powertrain into a ‘universal charger’ in order to suit all types of charging stations.
The system features a modified electric powertrain in which the electric motor and inverter have been specially adapted to handle the additional task of charging. The only extra component is a DC/DC converter which ensures an optimised and regulated power flow to the battery. The vehicle would be equipped for all types of charging technology, from single or three-phase AC to high-speed DC systems. In the case of an AC current, the current flows from the charging station via the electric motor to the inverter, where it is converted to into DC current before being supplied to the battery. For DC charging, the current flows directly from the charging station through the inverter to the battery.
The AllCharge technology can always use the maximum output rate at a charging station, up to 800v and 350 kW. Continental claim that the maximum benefit could be seen at urban charging station where up to 12 times faster charging may be possible, while the bidirectional system also provides 230v of AC power to the driver for onboard use.
Charging times will also be reduced through innovative battery technology, and Toshiba recently announced its next generation battery which could boost driving range for an electric vehicle to 320 km after a 6-minute, ultra-rapid recharge.
Toshiba’s next-generation SCiB uses a new material to double the capacity of the battery anode. Since launching SCiB in 2008, the tech firm has developed a titanium niobium oxide anode material that has double the lithium storage capacity by volume of traditional graphite-based anodes. Testing of a 50Ah prototype has demonstrated that the new battery retains the long life cycle, low temperature operation, and rapid re-charging characteristics of the current SciB. And that the next-generation SCiB retains 90% of its initial capacity after being put through 5,000 charge/discharge cycles.
Toshiba is continuing to develop the battery with the intention of commercializing the technology in 2019.
The landscape for electric vehicle charging is broad, with many stakeholders involved in the various trends and technological developments. In Europe, the CCS charging standard is moving to the fore, particularly in light of Porsche’s trail-blazing Mission E and 800v charging system.
The networks are beginning to develop at pace across Europe, and this will be crucial to the growth of electric vehicle ownership. As indeed will charge time, and Toshiba’s battery technology provides a glimpse of the imminent improvements in batteries which could be gamechangers. If the industry can crack the problems of both range and charge time, electric vehicles will be ready to take over the roads.