A critical review of the circular economy for lithium-ion batteries and photovoltaic modules – status, challenges, and opportunities

ABSTRACT

To meet net-zero emissions and cost targets for power production, recent analysis indicates that photovoltaic (PV) capacity in the United States could exceed 1 TW by 2050 alongside comparable levels of energy storage capacity, mostly from batteries. For comparison, the total U.S. utility-scale power capacity from all energy sources in 2020 was 1.2 TW, of which solar satisfied approximately 3%. With such massive scales of deployment, questions have arisen regarding issues of material supply for manufacturing, end-of-life management of technologies, environmental impacts across the life cycle, and economic costs to both individual consumers and society at large. A set of solutions to address these issues center on the development of a circular economy – shifting from a take-make-waste linear economic model to one that retains the value of materials and products as long as possible, recovering materials at end of life to recirculate back into the economy. With limited global experience, scholars and practitioners have begun to investigate circular economy pathways, focusing on applying novel technologies and analytical methods to fast-growing sectors like renewable energy. This critical review aims to synthesize the growing literature to identify key insights, gaps, and opportunities for research and implementation of a circular economy for two of the leading technologies that enable the transition to a renewable energy economy: solar PV and lithium-ion batteries (LIBs). We apply state-of-the-science systematic literature review procedures to critically analyze over 3,000 publications on the circular economy of solar PV and LIBs, categorizing those that pass a series of objective screens in ways that can illuminate the current state of the art, highlight existing impediments to a circular economy, and recommend future technological and analytical research. We conclude that while neither PV nor LIB industries have reached a circular economy, they are both on a path towards increased circularity. Based on our assessment of the state of current literature and scientific understanding, we recommend research move beyond its prior emphasis on recycling technology development to more comprehensively investigate other CE strategies, more holistically consider economic, environmental and policy aspects of CE strategies, increase leveraging of digital information systems that can support acceleration towards a CE, and to continue to study CE-related aspects of LIB and PV markets.

Acknowledgment

This work was authored in part by the National Renewable Energy Laboratory, operated by Alliance for Sustainable Energy, LLC, for the U.S. Department of Energy (DOE) under Contract No. DE-AC36-08GO28308. Funding was provided by the DOE's Advanced Manufacturing Office and Solar Energy Technologies Office, as well as through internal funding from the National Renewable Energy Laboratory. The views expressed in the article do not necessarily represent the views of the DOE or the U.S. Government. The U.S. Government retains and the publisher, by accepting the article for publication, acknowledges that the U.S. Government retains a non-exclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this work, or allow others to do so, for U.S. Government purposes. We would like to thank Teresa Barnes, Jill Engel-Cox, Hao Cui, Taylor Curtis, Matthew Keyser, Caitlin Murphy, Silvana Ovaitt, Stephanie Shaw, Timothy Silverman, Julien Walzberg, and the reviewers for their detailed feedback that helped us significantly improve this work. We would also like to thank Al Hicks for graphics support and Connor O'Neill for editorial support as well as Jen Walker, Jason Youngstrom and Claire Bolyard from the National Renewable Energy Laboratory library for helping us obtain scientific literature supporting this review.

Disclosure Statement

No potential conflict of interest was reported by the author(s).

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Notes on contributors

Garvin A. Heath

Garvin A. Heath, Ph.D., is an inaugural Distinguished Member of the Research Staff at the National Renewable Energy Laboratory (NREL), USA, specializing in the analysis of environmental impacts of energy systems – renewable and conventional, electricity and fuels.

Dwarakanath Ravikumar

Dwarakanath Ravikumar, Ph.D., is a Scientist at the National Renewable Energy Laboratory (NREL), USA, and focusses his research on operationalizing a circular economy for renewable energy infrastructure systems, especially photovoltaics (PV), and carbon dioxide through carbon capture and utilization (CCU).

Brianna Hansen

Brianna Hansen is a post-undergraduate intern at the National Renewable Energy Laboratory (NREL), USA, and focuses her research on the application of the circular economy to renewable energy systems, as well as the decarbonization of manufacturing industries and supply chains.

Elaine Kupets

Elaine Kupets is a post-undergraduate intern at the National Renewable Energy Laboratory (NREL), USA, researching applications of the circular economy to photovoltaics (PV), along with a focus in analyzing environmental health issues associated with end-of-life PV.