Contributed commentary by Stephen Voller, CEO and Founder, ZapGo Ltd.
Several nations, including England and China, have publicized plans to phase out traditional gas-powered vehicles in favor of electric vehicles (EVs). This has spurred debate over the technical challenges of scaling-up existing EV infrastructure and offering quick recharging for EV owners. New technology already offers ultra-fast charging for small electric vehicles and could sharply reduce EV recharging times in the future.
The Challenge of an EV Future
According to The New York Times, China has called for one out of five cars sold there to run on alternate fuel by 2025, and a Chinese official recently said the country would eventually do away with internal combustion engines in new cars. Meanwhile, Britain has announced a ban on the sale of new gasoline and diesel cars and vans in that country, starting in 2040, with the aim of reducing emissions.
All this will come at a cost: Reuters says Britain must plow billions into new power plants, grid networks and EV charging points if it is to avoid local power outages. Local networks particularly face problems, so the country will need a range of technologies for managing consumption to meet an estimated rise of up to 15 percent in overall demand and prevent spikes of up to 40 percent at peak times.
A related challenge involves how all these EVs are charged. According to a report by SO Energy Insights, it would take about 19 hours using a standard-sized 3.5-kilowatt charger to charge a 90 kilowatt-hour battery, which offers a 300-mile driving range, from 25 percent to 100 percent. This could be halved to 10 hours with a seven-kilowatt charger and further reduced to 80 minutes with a 50-kilowatt charger.
However, even with a 22-kilowatt charger, which would take three hours to fully charge, EV owners wouldn’t be able to use any other electrical equipment at home while charging, notes the SO Energy report. And in any event, 32 percent of low-voltage circuits across Britain would need reinforcing to allow most customers to use even the less-powerful 3.5-kilowatt chargers at home.
The amount of time it takes for drivers to fully recharge their vehicles ought to be a key consideration in any future scenario involving EVs, because this endeavor will not come cheap. Financial services firm Morgan Stanley has estimated the world will need to spend $2.7 trillion on charging infrastructure to support 500 million EVs.
The Feasibility of Ultra-Fast Charging
One potential avenue for alleviating these impractically long recharge times involves a burgeoning technology known as ultra-fast charging. In place of traditional lithium-ion batteries in EVs, this technology adopts a fast-charging and safer alternative involving a carbon-based alternative in place of lithium.
In contrast to lithium-ion, these alternative battery packs last much longer, specifically up to 100,000 charge and discharge cycles. These cells combine the fast-charging characteristics of a supercapacitor and, within a few years, are anticipated to match the energy density of lithium-ion batteries, while also being safe and recyclable (unlike lithium-ion). Also unlike lithium-ion, which works by an electrochemical reaction that is the source of the risks that have been publicized by the media, these cells pose no similar risk. This is because they incorporate a new, less-volatile type of electrolyte, called an “ionic electrolyte”, that does not contain any of the flammable chemicals in the “organic electrolytes” used in lithium-ion batteries.
Lithium-ion batteries will most likely always be commercially available in one form or another. However, the advantages of the carbon-based alternative may come to be recognized by EV manufacturers, and may be a progressively more popular option as time goes by and occupy an increasing portion of the market because of the perks they offer.
To achieve faster charging, this technology could be built into both a charging station and an EV so that the energy transfer occurs directly from one to the other. With this technology, the charge rate is not dependent on how much energy the EV can take in, or on the output of the electrical grid, as it is with conventional lithium-ion batteries. A 350-kilowatt charger would take less than four minutes to charge an average EV of today from 25 to 100 percent. The technology has already been successfully demonstrated in a four-person autonomous vehicle that recharges in just 35 seconds. A bank of these cells could be integrated into electric charging stations to ensure sufficient power to recharge EVs in the same time as it takes to fill a gas tank now.
It is fortunate that two revolutions are occurring more or less simultaneously: first, the push to convert large numbers of vehicles to EVs, reducing harmful effects of internal combustion engines on the environment; second, the advent of alternatives to lithium-ion batteries that enable the potential of ultra-fast charging. Together, these advances could transform the transportation options of tomorrow.
Stephen Voller, C.Eng. is CEO and founder of ZapGo Ltd., the developer of Carbon-Ion (C-Ion) cells, a fast-charging and safe alternative to lithium-ion batteries.
