Globally, the electrification of energy storage and mobility is driving an enormous demand for lithium-ion battery (LIBs), in which graphite electrodes play a crucial role. Unfortunately, the high-quality inventory data available for natural and synthetic battery-grade graphite remains inadequate for the development of meaningful LCAs. This article highlights some of the most significant gaps in existing inventory data. It also proposes solutions to reduce the environmental impact LIBs have.
Graphite electrodes are used in a range of applications from steel manufacturing and metallurgical process to recarburising, batteries and more. Batteries are the largest consumer of graphite, with 48%. Foundries, refractories products, friction materials, carbon shapes and lubricants are other applications. Despite the low percentage of graphite consumption in total, each application uses significant amounts of this material.
The most significant environmental impacts come from the mining and calcination processes that produce graphite. However, this is only one piece of the picture: In fact, the total life cycle footprint of graphite is significantly higher due to the underlying environmental impacts associated with the broader supply chain. These impacts include fine-particulate pollution, mineral resource depletion, fossil fuel consumption, and water consumption. Incorporating these impacts into LCAs is important to improve our understanding of the true impact of graphite production and support efforts to mitigate them.
In order to make LIB anodes more eco-friendly, it's important to recycle and upcycle the material. The research community has worked on developing anode alternatives that can replace graphite. The commercialization of these materials is in its early days, but it has been proven that they are capable of delivering comparable performance to traditional Graphite.
The research community must work on developing novel battery reutilization techniques in order to reduce the graphite used for LIB manufacturing. This can happen by optimizing re-utilization methods in terms on energy and material inputs.
This study focuses on the LCA of nine state-of-the-art graphite upcycling and recycling methods, evaluating their potential to enable lithium-ion battery anode material recycling through a gate-to-gate perspective. The results have been compiled into 18 standard ReCiPe 2016, midpoint impact indicator, with a special emphasis on material and energy consumption.
In contrast to other studies, impact data presented here are normalized by comparing them with the electrochemical performances of recycled graphite anodes (1 kWh as a unit of functional energy storage). This approach is preferred to studies that report results by comparing against a benchmark material. Since most LIB upcycling and recycling studies only evaluate the effects on different processing conditions which can lead to biased conclusions, this method is preferred. The study also shows how both hydrometallurgical (hydro-) and pyrometallurgical (pyro-) graphite recycling can be enhanced by minimizing acid use, optimizing temperature and reaction times, and using renewable energies instead of fossil fuels.
English
Write a Message