Overview of the environmental impact of lithium-ion batteries
As the core of modern energy storage technology, lithium-ion batteries play an irreplaceable role in promoting global energy transformation and transportation electrification, but their environmental impact throughout their life cycle has attracted great attention from the international community. From mineral mining to production and manufacturing, from consumption to scrapping, lithium-ion batteries face unique environmental challenges at each stage, which constitute a complex and multidimensional environmental impact matrix.
The environmental burden in the production stage is the most significant. For every kilowatt-hour (kWh) of lithium-ion battery produced, an average of 61-106 kg of carbon dioxide equivalent emissions will be generated. This figure covers the entire process from raw material extraction to battery assembly, with the production of positive electrode materials accounting for more than 40% of total carbon emissions. Taking ternary lithium batteries as an example, the mining and smelting process of metals such as nickel, cobalt, and manganese in its positive electrode materials not only consumes huge energy, but also produces a large amount of harmful gases such as sulfur oxides (SOx) and nitrogen oxides (NOx), as well as wastewater containing heavy metals.
The ecological damage caused by the development of mineral resources is particularly severe. About 58% of the world's lithium resources come from the "Lithium Triangle" region of South America (Argentina, Bolivia and Chile), where the salt lake brine lithium extraction process requires a large amount of groundwater extraction, resulting in the destruction of local water balance and the degradation of wetland ecosystems. As the world's main supplier of cobalt ore (accounting for more than 70% of global production), the artisanal mining operations in the Democratic Republic of the Congo not only cause serious soil and water pollution, but also are accompanied by poor labor conditions and human rights issues.
Although the use stage is relatively clean, there are still potential risks. Lithium-ion batteries usually do not directly emit pollutants during use, but improper use (such as overcharging, high temperature environment) may cause thermal runaway, cause fires and release toxic gases. In addition, the characteristic that battery performance gradually decays with the charge and discharge cycle also indirectly affects its environmental benefits. Reduced energy efficiency means an increase in the environmental cost of unit energy storage.
Scrap disposal constitutes the last link of the environmental impact of lithium-ion batteries, and it is also the most easily overlooked link. It is estimated that by 2030, the global scrap volume of power batteries will grow at an average annual compound growth rate of 43% to 1,483 GWh/year. If these waste batteries are not properly disposed of, the heavy metals and organic electrolytes in them may seep into the soil and water, and the fire risk caused by battery short circuits cannot be ignored. What's more serious is that the global recycling rate of waste lithium-ion batteries is still less than 5%, and a large amount of valuable metal resources are wasted.
Faced with these challenges, the international community has begun to take action. The EU's "New Battery Law" has established a full life cycle regulatory framework from production to recycling, and China has built more than 10,400 power battery recycling service outlets covering 31 provinces. At the same time, technological advances are constantly improving the environmental performance of lithium-ion batteries. New recycling processes can increase the recovery rate of metals such as copper and aluminum to 98%, and innovative technologies such as solid-state batteries are expected to fundamentally solve the environmental problems of traditional lithium-ion batteries. These efforts together constitute a multi-dimensional solution for the sustainable development of the lithium-ion battery industry.
