Finding new innovative and sustainable ways to produce carbon components for batteries and electric vehicles would help alleviate current strains on the supply chain and ease dependence on traditional carbon sources, including carbonaceous fillers and carbon-yielding binders, which are subject to harsh chemicals and machinery during mining and processing.
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Finding the technology and methods to do so is not always cheap, but the cost of not doing so could be even greater from an environmental perspective. Now, a team of researchers from Nanyang Technological University, Singapore (NTU Singapore) has developed a carbonization method for converting waste paper into pure carbon, which could be used in lithium-ion batteries.
Published in the journal Additive Manufacturing, the team reported how they were able to turn waste paper fibers into electrodes in rechargeable batteries that are suitable for use in a wider range of applications, such as electric vehicles, mobile phones, and even medical devices.
Durable, Green Anodes
To produce the electrodes, the team collected single-use kraft paper bags and then pressed them together before laser-cutting them into various lattice geometries, some of which resembled a starfish or spikey piñata. The geometric formations were then blasted with heat at around 1200 °C in a vacuum, which produced pure carbon structures that could be used as an anode.
One of the standout properties of waste paper-based anodes is durability which, when combined with their electrochemical capacity and flexibility, makes them well-suited for everyday use in a variety of applications. The team also claims that their green anodes are more durable than current anode materials and could potentially extend the life cycle of Li-ion batteries.
Our anodes displayed a combination of strengths, such as durability, shock absorption, electrical conductivity, which are not found in current materials. These structural and functional properties demonstrate that our kraft paper-based anodes are a sustainable and scalable alternative to current carbon materials, and would find economic value in demanding, high-end, multifunctional applications, such as the nascent field of structural batteries.
Mr. Lim Guo Yao, Research Engineer, School of Mechanical & Aerospace Engineering, NTU
Paper waste typically derives from cardboard, newspaper, single-use paper bags, and other packaging, all of which have a significant environmental footprint when compared to cotton and plastic packaging. Moreover, when incinerated, paper waste dramatically contributes to global warming, and there is a raised risk of eco-toxicity when it comes to the large-scale production of paper.
The innovative alternative fabricated by the team at NTU has the potential to recycle waste paper and reduce the environmental impact of single-use paper products. As well as pure carbon, the NTU team also reports that water vapor and oils can be converted into biofuel through the carbonization process.
Sketching Out The Future
Furthermore, as the carbonization process does not need oxygen to burn the waste paper fibers, it is more environmentally compatible compared to current incineration methods, which produce significant amounts of greenhouse gases.
Our method converts a common and ubiquitous material – paper – into another that is extremely durable and in high demand. We hope that our anodes will serve the world’s quickly growing need for a sustainable and greener material for batteries, whose manufacturing and improper waste management have shown to have a negative impact on our environment.
Auan Lai, Assistant Professor, NTU
While the team demonstrates environmentally compatible methods to produce economically viable carbon materials, in the future, they will focus on refining the process to further improve the energy storage capacity of the material while seeking ways to reduce the energy required to drive the carbonization process of turning waste paper into pure carbon.
References and Further Reading
Lai, C.Q. et al. (2022) “Exceptional energy absorption characteristics and compressive resilience of functional carbon foams scalably and sustainably derived from additively manufactured Kraft Paper,” Additive Manufacturing, 58, p. 102992. Available at: https://www.sciencedirect.com/science/article/pii/S2214860422003852?via%3Dihub
Converting waste paper into battery parts for smartphones and electric vehicles (2022) Corporate NTU. Available at: https://www.ntu.edu.sg/news/detail/converting-waste-paper-into-battery-parts-for-smartphones-and-electric-vehicles