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Project title

Rationally designed 3D-printed microlattice electrodes for next generation lithium-sulfur batteries

Primary Funding Agency

Irish Research Council

Co-Funding Organisation(s)

n/a

Lead Organisation

University College Cork (UCC)

Lead Applicant

n/a

Project Abstract

Single-Walled Carbon Nanohorns (SWCNHs) are a kind of carbon material characterized by horn shaped graphitic tubules (2-5 nm diameter and 40-50 nm tube length) which, upon aggregation, form dahlia-like, bud-like, and seed-like structures. Moreover, they can be mass produced (tons/year) using a novel proprietary process technology making them attractive for various industrial applications. Due to their high surface area, good conductivity, and unique geometrical structure, SWCNHs have found applications in gas storage and catalysis. However, the potential of SWCNHs for energy storage, especially in lithium-ion batteries, have not been explored. Inspired by their unique porous structure, I used nitrogen-doped Single walled Carbon Nanohorns (N-SWCNHs) as a conductive substrate for various cathode (Sulfur) and anode (Ge, Sn) active materials for lithium-ion batteries. The choice of nitrogen doping is motivated by the quest for improved interaction between SWCNHs and the surrounding active material. In particular, N-SWCNHs were used as porous conductive host for encapsulating sulfur using a simple melt-diffusion method. Electrochemical result obtained from N-SWCNHs-Sulfur composite showed high gravimetric capacities of 1650 mAh/g with high sulfur content of 80% (w/w). Later, pentagon and heptagon sites of N-SWCNHs were exploited by growing 5-10 nm Ge- nanocrystal around the cones of N-SWCNHs. The Ge@N-SWCNHs composite, when used as anode material, provided extremely stable and high gravimetric capacities of 1285 mAh/g at 0.1C after 100 cycles. Similar, results were obtained for Sn@N-SWCNHs composites, where a strong reducing agent (Lithium-Naphthalenide) was used to decorate Sn-nanocrystal on the surface of N-SWCNHs. Capacities as higher as 735 mAh/g were achieved at 0.1C even after 140 cycles. Finally, a fundamental study was performed to explore the mode of destruction in Sn electrode while sodiation/de-sodiation for sodium ion batteries. Our ex-situ SEM analysis confirmed the formation of pores during sodiation while cracks started to appear during the process of de-sodiation.

Grant Approved

�96,417

Research Hub

Climate related research

Research Theme

Achieving climate neutrality by 2050.

Start Date

01/09/2021

Initial Projected Completion Date

31/08/2023