Imagine a world powered by solar panels and wind farms, where electric cars are common, and almost all communication is digital. This transition toward a more sustainable world is gaining momentum.
In 2011, President Obama urged America to become the first country to have one million electric vehicles on the road by 2015. In his words, this was an important part of a "clean energy" revolution that would advance sustainability, expand the economy, and wean the nation from foreign sources of energy. Although electric auto sales have fallen short of President Obama's goals, sales grew more than 50% from 2012 to 2014, with more than 100,000 vehicles sold, and newcomers, like Tesla are aiming to manufacture 500,000 cars per year by 2020. The widespread use of electric cars promises a reduction in gasoline use and greenhouse gas emissions.
Although there has been a tremendous growth in solar and wind power over the last decade, energy storage remains the "missing piece" in the transition to a sustainable energy system. Most renewable energy sources are intermittent, since the sun doesn't always shine and the wind doesn't always blow. Energy storage technology will play an important role in allowing for more and more efficient use of renewable energy sources. Currently, batteries are being designed to provide storage capabilities, from the scale of a house to an entire neighborhood. http://thinkprogress.org/climate/2015/05/01/3653015/tesla-announces-home-battery/ https://vimeo.com/122735612 http://www.washingtonpost.com/news/energy-environment/wp/2015/09/16/why-using-solar-energy-at-night-is-closer-than-you-think/
One of the most pronounced transitions of the last decade has been the rapid growth of smart phones and tablets. It is estimated that 1.5 billion smart phones and 250 million tablets will be sold in 2015. The expectation is that more smart phones and tablets mean fewer newspapers, books, and magazines will be read on paper. Although manufacturing such devices and powering the internet are resource intensive, they more than offset the environmental costs of traditional media, since the production and distribution of books, magazines, and other paper-based products (even recycled paper products) consumers large amounts of water, energy, and other resources. http://repository.upenn.edu/cgi/viewcontent.cgi?article=1003&context=gsjod
In important ways, all of these technologies - tablets, electric cars, and renewable energy - are crucial to a more sustainable future. Yet, they all have one thing in common: they depend upon batteries. That raises an important question: just how environmentally sustainable are batteries?
Today, sustainability is a ubiquitous phrase: you can buy sustainable foods at the grocery store, review sustainability reports from major corporations, visit sustainable buildings, and purchase sustainable energy from electricity providers. Although the underlying concepts are old, the term itself is relatively recent: it was not until the 1990s, the term first began circulating in public discussion, before exploding in usage in the 2000s and 2010s. https://global.oup.com/academic/product/sustainability-9780199372409?cc=us&lang=en&
The most well-known definition of sustainability was set forth in a 1986 report commission by the United Nations titled Our Common Future. It defined sustainable development as "development that meets the needs of the present without compromising the ability of future generations to meet their own needs." It was particularly concerned with the importance of meeting the "essential needs" of the world's poor and observing the limits to the environment's abilities to meet "present and future needs." http://www.un-documents.net/our-common-future.pdf
Over time, the concept of sustainability has evolved to emphasize the interconnectedness of the environment, the social, and the economic. These are often described as the "three pillars" of sustainability. Sustainable development should strengthen all three pillars - social justice and equity, environmental conservation and protection, and economic development - simultaneously.
This approach can be modeled as a Venn diagram, that describes sustainability as the intersection or relationship between these different domains.
This concept can also be diagrammed as a set of concentric circles, with the environment at the outermost, encompassing domain. In this version, the environment is the foundation, upon which society, and, ultimately, the economy depend.
What does sustainability mean if you are examining a battery, a laptop, a car, or some other form of modern technology? Although batteries are important to many greener and more energy efficient technologies, adopting such technologies often means trading one set of sustainability challenges for another set: electric cars may reduce gasoline consumption, renewable energy systems may reduce coal or natural gas consumption, and tablets may reduce paper consumption, but each increases the demands for metals, chemicals, and other materials.
This does not mean that battery-based technologies are not environmentally preferable - electric cars are usually more environmentally friendly than gasoline-powered cars (although how your electric provider generates electricity matters) and the long-term use of tablets can be more environmentally friendly than paper consumption. But to assess the sustainability of these technologies, means considering carefully where materials are sourced from, what the working conditions are like, and what the broader social and environmental consequences are.
In the case of batteries, there are several approaches that can guide our consideration of the sustainability of modern technologies, all of which we draw upon on this website.
Where do batteries come from? How much electricity does it take to charge them? What happens when we recycle them? Those are the types of questions that a life-cycle analysis (LCA) can help answer. Life-cycle analyses consider the environmental inputs and burdens at each stage of a product's life, from mining raw materials to manufacturing and assembly to disposal or recycling at end-of-life.
For instance, although solar panels may generate clean, renewable energy once they are installed on a roof, to fully understand the sustainability of a solar panel, we also need to consider how much pollution is generated in sourcing and processing the raw materials, manufacturing the panel, shipping it from the factory, and installing it. http://www.epa.gov/nrmrl/std/lca/lca.html
In this project, we draw upon life-cycle analyses that have been undertaken for batteries. These studies rely upon large databases that track environmental inputs (such as raw materials, energy, and water) and environmental burdens (such as greenhouse gases or water pollution) resulting from the manufacture different types of batteries. Such analyses consider environmental impacts across a wide range of categories, such as global warming potential, land use transformation, and toxicity to humans. http://www.eiolca.net
What are the social and environmental health burdens of mining, manufacturing, and disposing of batteries? Studies of environmental justice have long demonstrated that environmental burdens are rarely distributed equally or fairly, whether in the United States or abroad. Industrial facilities, such as manufacturing plants and recycling facilities, are often located in areas that disproportionately affect people of color and the poor. Nor are the environmental policies that aim to address those problems always implemented evenly across communities, states, or countries. In some cases, stricter environmental laws in more developed countries have pushed dirty and polluting industries abroad. http://www.dscej.org https://ejatlas.org
To what extent are these concerns relevant to the production and disposal of batteries? Where is the lead, the cobalt, and other materials for batteries mined? How are workers and neighboring communities protected from pollution? Do such environmental and trade policies work? All of these are questions with environmental justice dimensions important to our research on batteries.
Batteries depend upon very specific metals and chemicals - indeed, many batteries are named for their constituent materials, such as lead-acid, alkaline manganese, nickel cadmium, or lithium-ion batteries.
What risks are there in depending upon these materials? If we begin using more and more batteries, will we become dependent on particular countries that control the supply of raw materials? Are some raw materials especially toxic, at risk of depletion, or difficult to process? Are some materials easily replaced by other raw materials? Studies of the "criticality of materials" offer answers to such questions.
Such studies analyze the availability of materials along three dimensions: Supply risk considers whether the supply of a material might be jeopardized due to geological scarcity, regulatory policies, or geopolitical factors. For instance, how much lithium is available? Is it only mined in conjunction with other materials? Is it controlled by a few countries? Might tighter environmental regulations limit mining and processing activities?
Environmental implications examines the consequences of extracting and processing materials. For instance, Is mining and refining manganese particularly energy intensive, does it use lots of water, or result in significant pollution? What are the consequences for human health and ecosystems?
Vulnerability to supply restrictions considers the uniqueness of a material. For instance, how important is the graphite used in many batteries? Are there readily available substitutes? How well do they perform? What percentage of these materials are imported? http://pubs.acs.org/doi/abs/10.1021/es203534z