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Adam Boies

Publications and source records attributed to Adam Boies.

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Securing the supply of graphite for batteries

Surging demand for graphite in energy storage applications has led to concerns about supply chai security for manufacturers and nations globally. Currently, China produces over 92% of graphite for anodes, posing a risk for industries reliant on graphite supply. Here, we systematically assess the costs of producing natural and synthetic battery-grade graphite in the U.S. and China using process-based cost models. We find that production costs in the U.S. are higher than those in China by 100-200%, so scaling production in the short-term will require significant policy support. We use our models to explore opportunities to improve the competitiveness of graphite production outside China, finding that lower financing rates and improved shaping yields can together reduce costs by 25-30%. Further implementing other cost reduction strategies, such as improving process throughput or lowering equipment costs, can achieve 35-40% lower costs. Finally, we discuss how innovative graphite production processes like methane pyrolysis and catalytic graphitization may provide competitive pathways.

econ.GN

Simultaneously Enhanced Tenacity, Rupture Work, and Thermal Conductivity of Carbon Nanotubes Fibers by Increasing the Effective Tube Contribution

Although individual carbon nanotubes (CNTs) are superior as constituents to polymer chains, the mechanical and thermal properties of CNT fibers (CNTFs) remain inferior to commercial synthetic fibers due to the lack of synthesis methods to embed CNTs effectively in superstructures. The application of conventional techniques for mechanical enhancement resulted in a mild improvement of target properties while achieving parity at best on others. In this work, a Double-Drawing technique is developed to deform continuously grown CNTFs and rearrange the constituent CNTs in both mesoscale and nanoscale morphology. Consequently, the mechanical and thermal properties of the resulting CNTFs can be jointly improved, and simultaneously reach their highest performances with specific strength (tenacity) $\rm\sim3.30\,N\,tex^{-1}$, work of rupture $\rm\sim70\,J\,g^{-1}$, and thermal conductivity $\rm\sim354\,W\,m^{-1}\,K^{-1}$, despite starting from commercial low-crystallinity materials ($I{\rm_G}:I{\rm_D}\sim5$). The processed CNTFs are more versatile than comparable carbon fiber, Zylon, Dyneema, and Kevlar. Furthermore, based on evidence of load transfer efficiency on individual CNTs measured with In-Situ Stretching Raman, we find the main contributors to property enhancements are (1) the increased proportion of load-bearing CNT bundles and (2) the extension of effective length of tubes attached on these bundles.

cond-mat.mtrl-sci