PerspectiveBattery Technology

# The coming electric vehicle transformation

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Science  25 Oct 2019:
Vol. 366, Issue 6464, pp. 422-424
DOI: 10.1126/science.aax0704

Electric vehicles are poised to transform nearly every aspect of transportation, including fuel, carbon emissions, costs, repairs, and driving habits. The primary impetus now is decarbonization to address the climate change emergency, but it soon may shift to economics because electric vehicles are anticipated to be cheaper and higher-performing than gasoline cars. The questions are not if, but how far, electrification will go. What will its impact be on the energy system and on geoeconomics? What are the challenges of developing better batteries and securing the materials supply chain to support new battery technology?

The signs of vehicle electrification are growing. By 2025, Norway aims to have 100% of its cars be either an electric or plug-in hybrid unit, and the Netherlands plans to ban all gasoline and diesel car sales by the same year. By 2030, Germany plans to ban internal combustion engines, and by 2040, France and Great Britain aim to end their gasoline and diesel car sales. The most aggressive electric vehicle targets are those set by China, which has almost half the global electric vehicle stock and where 1.1 million electric vehicles were sold in 2018. Europe and the United States each have just over 20% of the global stock, with electric car sales of 380,000 and 375,000 units, respectively, in 2018 (1, 2).

How far electrification will go depends primarily on a single factor—battery technology. In comparing electric with gasoline vehicles, all the downsides for electric arise from the battery. Purchase price, range, charging time, lifetime, and safety are all battery-driven handicaps. On the upside, electric vehicles have lower greenhouse gas emissions, provided the electricity grid that supports them is powered by renewable energy [the renewable share of global electricity is up from 22% in 2001 to 33% today (3), with Europe at 36%, China at 26%, and the United States at 18% (4)]. Moreover, the operation and maintenance costs of electric vehicles are substantially lower than for gasoline cars. Today, for high-mileage cars such as taxis, which typically travel 70,000 miles/year, the total cost of ownership of an electric vehicle, including purchase price, insurance, fuel, and maintenance, is much lower than for a gasoline car. This means that government and commercial fleets used for local service likely will convert to electric to save money, a major step in the electrification trajectory. To reach cost parity with personal gasoline cars, which typically travel 12,000 to 15,000 miles/year, battery prices must decline to near $100/kWh from the present value of$180 to \$200/kWh. Projections of the year of cost parity for electric vehicles with gasoline cars globally range from 2022 to 2026 (5, 6). At that point, economics could well take over as the primary impetus for electrification, and electric vehicles would then be on a path to transportation dominance.

An electric car in Milan, Italy, gets a charge. Grid-connected renewable energy systems, improved energy storage, and new battery technology will accelerate the electrification of transportation.

PHOTO: YOKO AZIZ/GETTY IMAGES

## Impact on Energy System

Electric vehicles will need to be charged from the grid, which may create as much as a 20 to 38% increase in electricity demand by 2050 (7). In developed countries, this should provide revenue for utilities to accelerate transformation to a grid-connected renewable energy system with extensive energy storage and to digital energy management. In developing countries, the increased electricity demand could spur the first-time installation of modern grids that are unencumbered by the legacy of the older, less functional grids of the developed world. Beyond electricity, electric vehicles require a massive rollout of charging stations, which could stimulate local economic and job growth.

Electric vehicles also should bring a welcome flexibility to the energy system. Untied from oil and gasoline, they would run on whatever powers the grid—sunlight, wind, natural gas, nuclear power, or hydropower. This removes a fundamental dependence of transportation on oil, including substantial amounts of foreign oil in many countries. Electricity is fundamentally a local product, not amenable to long-distance trade, so domestic economies should reap the economic and job benefits now held by foreign oil interests. The unification of transportation with electricity creates new horizons of opportunity for the grid as well. Electric vehicles are a readily available distributed energy resource of at least 1000 GWh, which represents 10% of the battery capacity of 100 million vehicles, each with a 100-kWh battery. The potential of this distributed energy resource for demand response and for grid storage has not yet been seriously explored.

## Impact on Geoeconomics

The electrification of transportation is a watershed moment in energy economics. For more than a century, oil has been the lifeblood of transportation, and the oil industry has grown steadily as transportation has expanded with industrialization and rising standards of living. But oil is abundant in relatively few countries, and these countries assume outsized geoeconomic importance because oil for transportation is a critical societal need. By contrast, sunlight and wind are available everywhere, and electricity generation is mostly a domestic enterprise. The electrification of transportation means that oil will lose one of its critical markets—and with it some of its international economic and political power.

What will replace oil as the lifeblood of transportation? The electrification of transportation creates a new commodity—not electricity, which is already established and abundant around the world, but battery technology. The battery is the key to electric transportation, the focal point for progress, and the open opportunity to determine the future of electric vehicles. Battery innovation is needed to achieve lower purchase price, faster charging, longer range, extended lifetime, and greater safety. These challenges do not yet have obvious solutions, but those who discover them will have substantial power in the battery marketplace.

## Battery Development

One of the most promising and disruptive battery innovations is the combination of lithium metal anodes and solid-state electrolytes. Every atom of a lithium metal anode can store and release energy during the charge-discharge cycle, whereas in graphite anodes now used in lithium-ion batteries, only 14% of the atoms (one lithium for every six carbons) can store or release energy. The greater capacity of the lithium metal anode could approximately double the energy density of the lithium-ion battery, extending the driving range of electric vehicles to compete with gasoline cars.

Solid-state electrolytes bring several advantages to lithium-ion batteries (8). They are not flammable, eliminating the primary safety hazard of lithium-ion batteries—the thermal runaway reaction that causes batteries to burst into flames if their temperature exceeds about 150°C. Some solid-state electrolytes, including sulfides such as Li2S–P2S5 (LPS) and garnets such as Li7La3Zr2O12 (LLZO), have high lithium-ion conductivity at room temperature, enabling the high-power performance needed for fast charging. Solid-state electrolytes conduct heat better than liquid electrolytes, protecting against the development of “hot spots” that trigger degradation and shorten battery life. In addition, the mechanical rigidity of solid-state electrolytes can block the growth of dendrites that form on the lithium metal anode surface and grow across liquid electrolytes to the cathode, shorting out the battery. These benefits of solid-state electrolytes are balanced by still-unresolved research challenges, including narrow working voltage windows, high reactivity with lithium anodes, and long-term stability.

There is now an intense drive to develop lithium metal anodes and solid-state electrolytes spanning academic, government, and industrial laboratories. Toyota announced its intention to have batteries with lithium anodes and solid-state electrolytes ready for electric vehicles by the early 2020s (9). The combination of lithium metal anodes with solid-state electrolytes would mark the first disruptive step in lithium-ion battery development, breaking a three-decade pattern of steady incremental advances in performance and cost (10).

## Material Supply Chains

Lithium, cobalt, manganese, nickel, and graphite are essential for battery technology, and some of these elements are found in only a few places in the world, not unlike oil (11, 12). The expected rapid increase in electric vehicle sales could threaten the supply chains for lithium, cobalt, and graphite in the short term because of the time required to ramp up new materials production and the relative scarcity of geographic sources. In the longer term, there are adequate resources in Earth's crust if lithium-ion batteries are recycled. Currently, less than 5% of Li-ion batteries are recycled, compared to more than 99.5% of lead-acid batteries. (13) Research and development to develop Li-ion battery recycling technology is an urgent need.

Batteries and their supply chains are the new oil; leadership in the battery and electric vehicle market requires strategically securing not only battery technology but also the battery materials supply chain. Recycling can play a substantial role in securing the supply chain for lithium-ion batteries, lowering costs by as much as 20% and supplying as much as 50% of the required materials (12). The nation or region that leads battery technology and secures its supply chain will have outsized influence on geoeconomics and world development.

## Global Landscape

Europe has grasped the electric vehicle opportunity, driven by its strict carbon emission requirements for future vehicles. The United States, by contrast, has proposed weakening its carbon emission requirements, and target dates for electrification of transportation are correspondingly farther out. In the International Energy Agency's New Policy Scenario (1), electric vehicles are projected to reach 26% of new car sales in Europe by 2030, but only 8% in the United States. China slightly leads Europe, with a 28% share of electric vehicles in 2030. In addition, China has moved strategically to secure its battery supply chain (11, 12). China now has the largest electrical vehicle market and the largest battery manufacturing enterprise in the world, amounting to 60% of the global capacity (14). It is well positioned to benefit economically and politically from the coming global electrification of transportation.

The electrification of transportation is far from complete. Buses, long-haul trucking, air taxis, and regional flight (15) remain relatively untapped opportunities. Batteries still must overcome challenges in cost, range, charging speed, safety, and lifetime for electric vehicles to dominate the market. Recycling is critical to sustainable supply chains but is still in its infancy. There are enormous opportunities for innovation in discovering solutions to these fundamental challenges. The innovating countries and regions will reap enduring economic and geopolitical benefits.

## References and Notes

1. International Energy Agency, Global EV Outlook 2019 (May 2019).
2. I. R. E. N. A. Renewable Capacity Statistics, 2019, Renewable Capacity Highlights (31 March 2019); www.irena.org/-/media/Files/IRENA/Agency/Publication/2019/Mar/RE_capacity_highlights_2019.pdf?la=en&hash=BA9D38354390B001DC0CC9BE03EEE559C280013F
3. Enerdata, Global Energy Statistical Yearbook 2019; https://yearbook.enerdata.net/renewables/renewable-in-electricity-production-share.html
4. Reuters, All the electric flying machines come home to roost at the Paris Airshow (19 June 2019); www.autoblog.com/2019/06/19/paris-air-show-electric-aircraft/.
Acknowledgments: This work was supported as part of the Joint Center for Energy Storage Research, an Energy Innovation Hub funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences.
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