Physics

Nanotechnology

Electrode

Porosity

Anode

Composite number

Endocrinology

Engineering

Carbon fibers

Physical chemistry

Composite material

Power (physics)

Chemistry

Materials science

Porous silicon

Lithium (medication)

Lithium-ion battery

Graphite

Cathode

Silicon

Battery (electricity)

Quantum mechanics

Chemical engineering

Optoelectronics

Carbon nanotube

Medicine

Nature Communications

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 (&gt;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 −2 ) deliver ~750 mAh g −1 specific capacity, &lt;20% initial swelling at 100% state-of-charge, and ~92% capacity retention over 500 cycles. Calendered electrodes achieve ~980 mAh cm −3 volumetric capacity density and &lt;50% end-of-life swell after 120 cycles. Full cells with LiNi 1/3 Mn 1/3 Co 1/3 O 2 cathodes demonstrate &gt;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.

Hierarchical porous silicon structures with extraordinary mechanical strength as high-performance lithium-ion battery anodes