As lithium-ion batteries (LIBs) become vital energy source for daily life and industry applications, a large volume of spent LIBs will be produced after their lifespan. Recycling of LIBs has been considered as an effective closed-loop solution to mitigate both environmental and economic issues associated with spent LIBs. While reclaiming of transition metal elements from LIB cathodes has been well established, recycling of graphite anodes has been overlooked. Here, we show an effect upcycling method involving both healing and doping to directly regenerate spent graphite anodes. Specifically, using boric acid pretreatment and short annealing, our regeneration process not only heals the composition/structure defects of degraded graphite but also creates functional boron-doping on the surface of graphite particles, providing high electrochemical activity and excellent cycling stability. The efficient direct regeneration of spent graphite by using low cost, non-volatile and non-caustic boric acid with low annealing temperature provides a more promising direction for green and sustainable recycling of spent LIB anodes.
As the dominant means of energy storage technology today, the widespread deployment of lithium‐ion batteries (LIBs) would inevitably generate countless spent batteries at their end of life. From the perspectives of environmental protection and resource sustainability, recycling is a necessary strategy to manage end‐of‐life LIBs. Compared with traditional hydrometallurgical and pyrometallurgical recycling methods, the emerging direct recycling technology, rejuvenating spent electrode materials via a non‐destructive way, has attracted rising attention due to its energy efficient processes along with increased economic return and reduced CO2footprint. This review investigates the state‐of‐the‐art direct recycling technologies based on effective relithiation through solid‐state, aqueous, eutectic solution and ionic liquid mediums and thoroughly discusses the underlying regeneration mechanism of each method regarding different battery chemistries. It is concluded that direct regeneration can be a more energy‐efficient, cost‐effective, and sustainable way to recycle spent LIBs compared with traditional approaches. Additionally, it is also identified that the direct recycling technology is still in its infancy with several fundamental and technological hurdles such as efficient separation, binder removal and electrolyte recovery. In addressing these remaining challenges, this review proposes an outlook on potential technical avenues to accelerate the development of direct recycling toward industrial applications.
more » « less- NSF-PAR ID:
- 10395347
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Advanced Functional Materials
- Volume:
- 33
- Issue:
- 14
- ISSN:
- 1616-301X
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
more » « less
-
more » « less
Abstract Lithium‐ion batteries (LIBs) are a key technology in decarbonizing the transportation and electricity sectors, yet the use of critical materials, such as cobalt, nickel, and lithium, lead to environmental and social impacts. Reusing, repurposing, and recycling mitigate battery impacts by extending their lifespan and reducing reliance on virgin materials. Innovation that reduces demand for these problematic materials and increases battery efficiency also reduces impacts. Two examples of this technological innovation include, (1) the development of energy dense cathode chemistry containing less cobalt, a material with high social and environmental impacts; and (2) the use of columnar silicon thin film anode, which results in increased energy density compared to the commonly used graphite anode. This research assesses whether these technological innovations change the currently understood waste hierarchy, which prioritizes reuse or repurposing prior to recycling. This is of interest because retired high‐cobalt batteries could supply their constituent materials sooner if recycled immediately and be used in low‐cobalt, higher‐performing batteries. The assessment considers the life cycle environmental impacts of two end‐of‐life management routes for a high‐cobalt LIB: first, recycling the battery immediately after the first use life to produce a new, and less material intensive battery, and second, repurposing the battery for a stationary storage application followed by recycling. Findings show that battery reuse reduces life cycle environmental impacts relative to immediate recycling. Thus, from an environmental perspective, the waste hierarchy holds, and steps to retain the batteries in their highest value use, such as through repurposing, should still be prioritized.
-
The rapid expansion of electric vehicle (EV) fleet calls for large number of lithium-ion batteries to be recycled at their end-of-life. Various recycling methods have been developed or under development to recover the high-value materials from retired lithium-ion batteries. Amongst these methods, direct recycling techniques have been developed and reported to recycle battery materials for reuse in new battery manufacturing since the electrochemical properties of the recycled materials can be fully recovered to the same level of pristine materials. In literature, innovative sintering processes have been developed to recover the composition and crystal structure of spent cathode materials; hydrothermal regeneration processes have been reported to regenerate the spent cathode materials in the solvents at a moderate temperature, followed by the high-temperature short annealing process. The regenerated cathode materials show the same specific capacity and cycling performance as those of pristine materials. The electrochemical regeneration method is applied to fully recover the electrochemical performance of cathode material with stable crystal structure. While the direct recycling techniques are still under development, their future applications in industry are still not clear. This study aims to classify and summarize state-of-the-art of the direct recycling methods, and evaluate the regenerated cathode materials’ performance and the application potential to be used for manufacturing of new lithium-ion batteries in future. The results will help increase understanding of the direct recycling technologies and facilitate the associated R&D for future industrial scaling-up of direct recycling processes for retired lithium ion batteries from electric vehicles.more » « less
-
Electrochemical energy storage is a cost-effective, sustainable method for storing and delivering energy gener- ated from renewable resources. Among electrochemical energy storage devices, the lithium-ion battery (LIB) has dominated due to its high energy and power density. The success of LIBs has generated increased interest in sodium-ion battery (NaB) technology amid concerns of the sustainability and cost of lithium resources. In recent years, numerous studies have shown that sodium-ion solid-state electrolytes (NaSEs) have considerable potential to enable new cell chemistries that can deliver superior electrochemical performance to liquid-electrolyte-based NaBs. However, their commercial implementation is hindered by slow ionic transport at ambient and chemical/ mechanical incompatibility at interfaces. In this review, various NaSEs are first characterized based on individual crystal structures and ionic conduction mechanisms. Subsequently, selected methods of modifying interfaces in sodium solid-state batteries (NaSSBs) are covered, including anode wetting, ionic liquid (IL) addition, and composite polymer electrolytes (CPEs). Finally, examples are provided of how these techniques improve cycle life and rate performance of different cathode materials including sulfur, oxide, hexacyanoferrate, and phosphate-type. A focus on interfacial modification and optimization is crucial for realizing next-generation batteries. Thus, the novel methods reviewed here could pave the way toward a NaSSB capable of with- standing the high current and cycle life demands of future applications.more » « less
-
more » « less
Abstract Rapid adoption of lithium‐ion batteries for electronics and electric vehicles requires cost‐effective and efficient recycling of battery components especially the valuable cathode active materials. The direct recycling method transforms end‐of‐life (EOL) cathode materials into battery grade materials with minimal energy consumption and least environmental disruption. In direct recycling, the relithiation step to restore the lithium stoichiometry of the cathode materials is critical. In this work, a novel electrochemical relithiation approach in an aqueous electrolyte followed by a heat treatment for recycling cathode materials in EOL lithium‐ion batteries is demonstrated and analyzed. Using LiCoO2as an example, it is shown that the recycled LiCoO2materials show equivalent crystal structure, morphology, and electrochemical performance to the commercial LiCoO2.
