Lithium-ion batteries

Lithium-ion batteries are some of the most commonly used batteries today. But are they a good solution to the energy storage problem? Short answer: no.

Concerns

#Need for cobalt	Major problem
#Need for lithium	Minor problem
#Energy in manufacturing	Manageable
Recycling	Probably solvable
Performance in winter	Manageable

Need for cobalt

Suppose all vehicles ran on lithium-ion batteries:

ev.battery

65.2 kWh

Energy capacity of the average electric vehicle battery

Useable battery capacity of full electric vehicles
https://ev-database.org/cheatsheet/useable-battery-capacity-electric-car

world.cars

1.446 billion

How Many Cars Are There In The World in 2022?
https://hedgescompany.com/blog/2021/06/how-many-cars-are-there-in-the-world/

commercial_factor

2

Without this, we'd be calculating for just personal vehicles. But we also need to factor in commercial vehicles such as buses and trucks. These vary widely in size, and data is hard to find, so for simplicity sake, we just assume that they'd add up to about the same as personal vehicles - thus doubling total energy storage needed. This assumption is based on the fact that freight trucks are a somewhat smaller share of energy demand than passenger vehicles, but the trucks probably need a longer range.

li_ion.cell_voltage

3.6 volts

Voltage of a single lithium-ion cell.

https://www.cei.washington.edu/education/science-of-solar/battery-technology/
https://www.fluxpower.com/blog/what-is-the-energy-density-of-a-lithium-ion-battery
It's 3.6 volts for the "cobalt type" of lithium-ion battery. Other types might have a very slightly different voltage.

li_ion.lithium_by_energy

0.3 grams per amp hour li_ion.cell_voltage

To store a given amount of energy in lithium-ion batteries, this is how much lithium would be needed.

https://batteryguy.com/kb/knowledge-base/how-to-calculate-the-lithium-content-in-a-battery/
The article says lithium per amp hour. We convert this to lithium per watt hour (energy), by including the cell voltage.

lithium.reserves

18425000 tonnes

Lithium metal: Total global mineral reserves

https://www.statista.com/statistics/268790/countries-with-the-largest-lithium-reserves-worldwide/
Added up all the countries: 9,200,000 + 4,700,000 + 1,900,000 + 1,500,000 + 750,000 + 220,000 + 95,000 + 60,000 = 18,425,000 metric tons

li_ion.cobalt_by_energy

20 kg per 100 kilowatt hours

To store a given amount of energy, in lithium-ion batteries (cobalt type), this is how much cobalt would be needed.

https://www.energy.gov/eere/vehicles/articles/reducing-reliance-cobalt-lithium-ion-batteries

cobalt.reserves

7.1 million tonnes

Cobalt metal: Total global mineral reserves

https://www.statista.com/statistics/264930/global-cobalt-reserves/

li_ion.cobalt_by_energy * world.cars * ev.battery * commercial_factor % cobalt.reserves (calculation loading) So, besides needing far more cobalt than we could ever mine from the earth(...)( well, technically maybe we'd find more cobalt reserves, but don't count on it ), there would also be major environmental damage and child labor if we tried.

This problem could maybe be overcome by solving lithium-ion/challenge 1.

Need for lithium

Consider a similar calculation for lithium: li_ion.lithium_by_energy * world.cars * ev.battery * commercial_factor % lithium.reserves (calculation loading) At least it's viable - although there would still probably be a big environmental footprint.^{[QUANTIFICATION needed]} We'd have to make sure that all EV batteries eventually get recycled.

Note: this still doesn't include the additional energy storage we'd need on the power grid if solar and wind were major energy sources. This is less than what's needed for vehicles, but in total we'd probably slightly exceed global lithium reserves.

Energy in manufacturing

Averaged over the lifespan of the vehicle:

li_ion.rq_energy

57 kWh per kWh

Energy required to manufacture a lithium-ion battery

Factory energy only. DOES NOT include the energy involved in mining the materials.

"Based on public data on two different Li-ion battery manufacturing facilities, and adjusted results from a previous study, the most reasonable assumptions for the energy usage for manufacturing Li-ion battery cells appears to be 50–65 kWh of electricity per kWh of battery capacity."
Source:
Energy use for GWh-scale lithium-ion battery production
Institute of Physics - IOP Publishing
https://iopscience.iop.org/article/10.1088/2515-7620/ab5e1e

ev.lifespan

8 years

li_ion.rq_energy * ev.battery / ev.lifespan kWh/day (calculation loading)

Compared to how much energy you'd expect to consume by using the vehicle:

average_us_vehicle.mileage_by_time

32 miles/day

Distance driven by the average American vehicle

Top Numbers Driving America's Gasoline Demand
https://www.api.org/news-policy-and-issues/blog/2022/05/26/top-numbers-driving-americas-gasoline-demand

electric_car.efficiency

100 miles per 34.6 kWh

The "gas mileage" equivalent for an average electric car.

Average Electric Car kWh Per Mile [Results From 231 EVs]
ecocostsavings.com/average-electric-car-kwh-per-mile
Data originally from epa.gov/fueleconomy

li_ion.charge_discharge_efficiency

85%

When you charge a lithium-ion battery, this much of the energy can be recovered. The rest is lost as heat.

Range: 80 to 90 %
from wikipedia; haven't found original source yet

average_us_vehicle.mileage_by_time / electric_car.efficiency / li_ion.charge_discharge_efficiency kWh/day (calculation loading)

From this perspective, it seems that the energy in manufacturing the battery is reasonable enough.

Note: This doesn't include the energy involved in mining for the minerals to make the battery. (...)( In general, the rarer the mineral, the more energy it takes to mine. ) But we already saw earlier that mining (cobalt) was a problem regardless.

Similar calculations could be done for non-vehicle energy storage.

See also

• Sodium-ion batteries - a possible solution