Hierarchical porous silicon structures with extraordinary mechanical strength as high-performance lithium-ion battery anodes.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 32193387.
- Also identified by DOI 10.1038/s41467-020-15217-9 and PMC identifier 7081208.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Porous structured silicon has been regarded as a promising candidate to overcome pulverization of silicon-based anodes. However, poor mechanical strength of these porous particles has limited their volumetric energy density towards practical applications. Here we design and synthesize hierarchical carbon-nanotube@silicon@carbon microspheres with both high porosity and extraordinary mechanical strength (>200 MPa) and a low apparent particle expansion of ~40% upon full lithiation. The composite electrodes of carbon-nanotube@silicon@carbon-graphite with a practical loading (3 mAh cm<sup>-2</sup>) deliver ~750 mAh g<sup>-1</sup> specific capacity, <20% initial swelling at 100% state-of-charge, and ~92% capacity retention over 500 cycles. Calendered electrodes achieve ~980 mAh cm<sup>-3</sup> volumetric capacity density and <50% end-of-life swell after 120 cycles. Full cells with LiNi<sub>1/3</sub>Mn<sub>1/3</sub>Co<sub>1/3</sub>O<sub>2</sub> cathodes demonstrate >92% capacity retention over 500 cycles. This work is a leap in silicon anode development and provides insights into the design of electrode materials for other batteries.