Lithium-ion batteries-rechargeable secondary cell batteries are often used as energy storage units. As the name suggests, lithium-ion batteries are cells which consist of lithium metal oxide ions in their positive electrode and carbon ions in the negative side. Lithium batteries have many positive uses apart from being rechargeable secondary cells. For instance, they charge extremely fast, are long-lasting, and are more temperature constant. Properties like these make it more useful for specific use in storage units. In addition, their fast-charging property is useful for time-sensitive machines and safer to use than lead batteries. At the same time, Lithium-ion batteries have many advantages, including extremely high energy storage efficiency and their small sizes, making them easily portable. Unfortunately, these batteries have adverse effects on the environment; extraction of lithium for the production of lithium-ion is highly harmful to the soil. It is a massive cause of soil pollution.

Furthermore, during lithium-ion extraction, large amounts of the metal mixed with other environmentally toxic metals may contaminate water sources, which, when ingested by people of the area, will have adverse effects on their health. In addition, lithium batteries also contribute to toxic waste, contribute to biodiversity loss, and increase the salinity of water. Due to their low availability, they are costly and not affordable for less economically developed countries to use as mass storage units. Although lithium-ion batteries have incredibly harmful effects on the environment, they are huge factors in energy storage. Lithium-ion battery usage as energy storage units could reduce the use of toxic energy source products such as fossil fuels and petrol. So while lithium-ion batteries are not safe for the environment, they have benefits in sustainable energy production. 

Sources: https://www.solar.com/learn/how-green-are-home-batteries-the-environmental-impact-of-lithium-ion/

https://newspatrolling.com/why-lithium-ion-batteries-are-so-expensive/

https://en.wikipedia.org/wiki/Environmental_impacts_of_lithium-ion_batteries#:~:text=Lithium%2Dion%20batteries%20contain%20metals,disposal%20of%20lithium%2Dion%20batteries.

https://www.enelgreenpower.com/learning-hub/renewable-energies/storage/lithium-battery#:~:text=Lithium%20batteries%20have%20very%20interesting,on%20a%20singular%20module%20level.