Batteries: Why Does Cobalt Matter?

batteries energy storage chemistry
Cobalt, a common mineral in lithium-ion batteries, has environmental, safety, and even social concerns.

Batteries are gaining popularity fast, and their cost is going down more quickly than expected. Batteries can help keep the lights on during an outage and save you money during times when the grid charges higher rates. Energy storage is bringing the world closer to fully embracing renewable energy. See our last blog post for more details about how batteries are useful. There is a lot of information to digest when deciding on a battery system: capacity, price, and warranty all impact your investment. Additionally, safety and the environmental impact of a battery’s components are particularly worth considering. At Brighten Solar Co., we have decided to only install batteries that are free of cobalt, and we’re here to help you understand why we think that is an important choice.

What Does Cobalt Do?


energy storage battery chemistry
Source: Electrek


Cobalt is used as a cathode in lithium-ion batteries. All batteries need to store energy is a cathode, anode, and an electrolyte. Lithium-ion batteries, like the ones in your smartphone, laptop, or electric vehicle, use lithium as their electrolyte and usually graphite or silicon as an anode. The choice of cathode makes a big difference in the characteristics of the battery, as well as its environmental impact. Many lithium-ion batteries use cobalt as a component because it allows for a high energy density. Storing a lot of energy in a small space is important for a battery, especially for uses in cell phones and other small consumer electronics. Cobalt is also useful for releasing a large amount of electricity at once, like for accelerating a Tesla 0-60 in 2.5 seconds.

Cobalt is not the only type of cathode available in batteries, but it is common. Companies like LG, Panasonic, and Tesla rely on cobalt for making their batteries. Alternatives like manganese and lithium iron phosphate batteries are also used, and come with their own pros and cons.





Why Shouldn’t I Use Cobalt?

When storing electricity for a home or a business, it is less important to be as small as possible and have a high output. Safety characteristics and durability become more important when considering a battery for your home. Using cobalt has drawbacks in the functioning of the battery, for the environment, and for the people who mine it.

Cobalt batteries have a more limited temperature range that they can operate in than other battery alternatives. Additionally, they run the risk of thermal runaway, which is a lot like it sounds: a positive feedback loop causes the temperature to skyrocket and the battery to explode or catch fire. This is not exactly ideal for equipment stored inside a building, especially in Santa Barbara’s dry, fire-prone climate.

It is also difficult to guarantee that the cobalt that is in your battery came from an ethically-sound source. The world’s reserves of economically accessible cobalt are heavily concentrated in the Democratic Republic of the Congo. About half of the world’s reserves are located there, and in most years the DRC is responsible for over half of the world’s production of cobalt. This concentration in the DRC is problematic because of the mining methods practiced there and the political instability of the area.

Corruption in the Congolese government means that much of the wealth gained from natural resource extraction never makes its way to providing the services that people need. Hundreds of millions of dollars in mining revenue has gone missing under the current regime. Instead, much of that money is funneled to private wealth and the funding of dangerous militias. Violence in the central region of the country has left up to 5,000 people dead since August of 2016. To combat this, the United States passed a conflict-minerals law in 2010 to install safeguards ensuring that the purchase of any of four selected minerals was not funding Congolese militias. Although it is not believed that cobalt mining is directly contributing to wars, many believe that it should be included so that human rights abuses can be avoided.

Human rights abuses are a concern because 10-25% of global production of cobalt is from artisanal mining. This is a dangerous form of mining with hand tools that often leads to injury and has little protection for workers. Children are often involved in artisanal mining, only worsening the human rights issue. Exposure to toxic metals in the mining of cobalt by hand has been linked to respiratory problems and birth defects.

The mining of cobalt has serious ecological impacts as well. The illegal mining of minerals in the DRC is destroying the habitat of endangered animals like the Eastern Lowland Gorilla. The subspecies’ population has decreased by over 75% in the last 18 years as a result.


That Sounds Terrible, Should I Still Get Batteries?

The good news is that there are alternatives to cobalt batteries, so we can avoid the ethical and safety dilemmas that come with this mineral. Brighten only installs Lithium Iron Phosphate batteries to be used in home energy storage solutions. Iron and phosphorous do not carry the same environmental and ethical issues in their use, and have proven themselves in thermal and puncture safety tests. 

On the side of battery functionality, lithium iron phosphate batteries have great benefits as well. They can operate in a wider range of temperatures and are not susceptible to thermal runaway. They tend to last much longer than cobalt batteries, usually guaranteed for 10 years or 10,000 cycles. The trade-off is a slightly lower energy density.

When considering the cost, functionality, environmental impact, and ethics of different home energy solutions, it was clear to Brighten that the ethical issues and environmental costs outweigh the benefits of cobalt-based lithium-ion batteries.


But I Still Need A Cell Phone…

Most cell phone batteries are mainly made with cobalt. Be sure to recycle cell phone and other lithium-ion batteries in order to reduce the demand for minerals like cobalt. The Santa Barbara Zoo has Ecocell boxes where you can drop off your battery for recycling. If you have any further questions about batteries or what system may be best for you, we would love to help.