Electric vehicle charging still takes too long, but a solution is on the horizon

Stephen Voller

Stephen Voller

The UK Government recently announced a total ban on the sale of new petrol and diesel vehicles from 2040. While this move will certainly be beneficial for the environment, there are a set of significant challenges to be addressed in the intervening 22 years. Collectively, overcoming them will ensure that the owners of battery electric vehicles – which may number in the millions in a matter of decades, up from less than 200,000 today – will be able to operate their vehicles in a convenient manner. 

Specifically, there are three distinct but related challenges that will need to be overcome: establishing an adequate driving range for electric vehicles; providing sufficiently fast charging times; and ensuring that appropriately high levels of energy can be transferred from the existing electrical grid to electric vehicle charging stations.

The solutions to these challenges may lie in a process that is known as extreme fast charging. This can give electric vehicle owners the ability to recharge their vehicles in as little as five minutes, as quickly and conveniently as filling up a conventional vehicle with gasoline. The UK currently lacks the infrastructure to support this technology on a wide scale but exciting technological developments offer an innovative potential approach to bridging this gap.

Range anxiety is commonly cited as one current reason for consumers’ hesitation to buy a battery electric vehicle. Extreme fast charging technology has the potential of overcoming this roadblock, making battery electric vehicles a practical solution for long-distance travel. At the very high charge rates permitted by extreme fast charging, battery electric vehicles can achieve a 300-mile range in just five minutes.

This range can be enabled by the incorporation into battery electric vehicles of a burgeoning technology known as Carbon-Ion (C-Ion). C-Ion technology does not require any of the lithium, cobalt, nickel or sodium needed in traditional electric vehicle batteries, and negates the growing concerns about ocean mining to obtain some of these elements. C-Ion cells represent a novel class of energy storage device that incorporates advanced nano-structured carbons, an ionic electrolyte and improved fabrication techniques. They can be easily utilised alongside existing lithium-ion cells on board electric vehicles. 

A dramatic reduction in charge time is crucial to the wider adoption of electric vehicles, according to a 2017 report by the US Department of Energy. The automotive industry believes that drivers will demand a recharge time of between five and 15 minutes. Most currently-installed charging stations have a maximum charge rate of about 30kW, which falls significantly short of what is needed to achieve these times. 

With the use of C-Ion cells, energy can be safely transferred to electric vehicles using extreme fast charging rates greater than 350kW. This can help ensure that the wait time at the charge station can be reduced to five minutes or less. This ultra-high transfer rate is possible because C-Ion can charge and discharge very quickly, and also because C-Ion does not catch fire, so it is perfectly safe to have a large energy store on site next to existing storage tanks of gasoline and diesel. Where filling station sites already have electric vehicle charge points, these can be upgraded to 350kW by installing this system.

The National Grid in the UK is currently unable to support extreme fast charging stations. With conventional technology, this problem could be resolved only by the use of new high-capacity electrical cable between the charging point and the nearest electricity substation, which could be located miles away, and would require streets to be dug up and new infrastructure installed along the route. 

This process could cost millions of pounds and take several years to plan and complete. And there is the question of whether enough charging stations would be available: this problem is most acute for those living in urban areas, who currently suffer from a lack of convenient charging options. With nowhere to recharge in the vicinity of their apartments, they would be forced to seek out stations located at an inordinately long distance from home.

To resolve this issue, banks of C-Ion cells could be used to buffer the grid. Very-high-rate direct current (DC) chargers could then be connected to the C-Ion banks operating at 350kW, 450kW or even as high as 1,000kW. These DC chargers could be installed at filling stations, city centre sites or shopping malls without the need to install new grid infrastructure. 

To minimise capital investment and the price of electricity, large containers could be installed on sites that initially contain 1MWh of stored energy in their C-Ion cells. At heavily-used charging stations, multiple containers may be installed. 

Extreme fast chargers of 350kW could be installed on site, connected to the container storage, not directly to the site grid connection, and vehicles could be charged from the stored energy at the 350kW rate. And because C-Ion cells have very rapid charge and discharge characteristics, the C-Ion banks can be filled up at night or when electricity is off-peak – ensuring that the cost of the energy required to keep these stations fully charged is minimised, meaning less financial strain for the government and electric vehicle owners alike. 

With an electric vehicle future clearly approaching in a range of nations around the globe, overcoming the current technological gaps is a must. Ongoing progress in overcoming these challenges today points the way toward a cleaner tomorrow.   

Stephen Voller is chief executive officer and founder of ZapGo Ltd, the developer of Carbon-Ion™ (C-Ion®) cells, a fast-charging and safe alternative to lithium-ion batteries.