Sustainable conversion of biomass to rationally designed lithium-ion battery graphite

Abstract

The carbon net negative conversion of bio-char, the low value byproduct of pyrolysis bio-oil production from biomass, to high value, very high purity, highly crystalline flake graphite agglomerates with rationally designed shape and size tailored for lithium-ion battery energy storage material is reported. The process is highly efficient, 0.41 g/Wh; the energy content of its co-product of the process, bio-oil, exceeds that needed to power the process. It is shown that the shape of the starting material is retained during the transformation, allowing the ultimate morphology of the graphite agglomerates to be engineered from relatively malleable biomass. In contrast to commercial graphite production, the process can be performed at small scale with low equipment costs, enabling individual research laboratories to produce Li-ion grade graphite with customizable shape, size and porosity for Si/graphite composite and other graphite involved anodes. The mechanism of the graphitization of bio-char, a “non-graphitizable” carbon, is explored, suggesting the molten metal catalyst is absorbed into the pore structure, transported through and transforming the largely immobile biochar. Finally, the transformation of biomass to rationally designed graphite morphologies with Li-ion anode performance that closely mimic commercial shaped graphite is demonstrated.

Insights into the Impact of Activators on the ‘Catalytic’ Graphitization to Design Anode Materials for Lithium Ion Batteries

“…recently reported the synthesis of highly crystalline flake graphite particles using hardwood sawdust and 62.5 wt. % iron powder by a laser pyrolysis [23a] . In that study, a maximum reversible capacity of 358 mAh g −1 was achieved in Li metal cells, which is similar than for commercial synthetic graphite materials.…”

Electrochemical graphitization transformation of deposited carbon for Li-ion storage: sustainable energy utilization from coke oven solid waste

“…12–14 In order to cope with the global energy crisis and environmental pressure, it is hence necessary to develop useful synthetic graphite. 15…”

“…[12][13][14] In order to cope with the global energy crisis and environmental pressure, it is hence necessary to develop useful synthetic graphite. 15 Currently, researchers attempt to prepare synthetic graphite from a variety of materials, including semi-coke, 16 bituminous coal, 12 waste PET plastic, 13 poly vinyl alcohol 17 and lignin. 18 However, excellent precursors should be sustainable, inexpensive, and easily accessible.…”

“…However, the current mainstream high-temperature (3000 °C) method to produce graphite is highly energy-intensive, and it has detrimental effects on the environment. 15,28 Although the addition of various new and efficient catalysts can reduce the temperature of graphitization, 29,30 the catalyst remaining in the graphite product generally limits the application of the catalytic graphite. 30 In order to further reduce the processing energy consumption and the adverse effects of production methods, researchers have made many attempts for graphitization.…”

Biomass Alginate Derived Oxygen-Enriched Carbonaceous Materials with Partially Graphitic Nanolayers for High Performance Anodes in Lithium-Ion Batteries

“…That is why it is more appealing than ever to employ functional group-rich materials as carbon precursors. Instead, biomass resources are thought to adequately cover the needs since they are renewable, low-cost, and ecologically beneficial [ 28 , 29 , 30 ]. Biomass is an abundant carbon source that may be processed into carbon compounds by carbonization, pyrolysis, and activation techniques.…”