US 11,840,454 B2
Hollow porous silicon-containing structures and method of formation
Srikanth Pilla, Clemson, SC (US); Morteza Sabet, Clemson, SC (US); Apparao M. Rao, Clemson, SC (US); and Nancy Chen, Clemson, SC (US)
Assigned to CLEMSON UNIVERSITY, Clemson, SC (US)
Filed by CLEMSON UNIVERSITY, Clemson, SC (US)
Filed on Nov. 12, 2021, as Appl. No. 17/525,497.
Claims priority of provisional application 63/113,399, filed on Nov. 13, 2020.
Prior Publication US 2022/0153597 A1, May 19, 2022
Int. Cl. C01B 33/20 (2006.01); C01B 33/149 (2006.01); H01M 4/86 (2006.01); H01M 4/38 (2006.01); B82Y 30/00 (2011.01)
CPC C01B 33/149 (2013.01) [C01B 33/20 (2013.01); H01M 4/386 (2013.01); H01M 4/8626 (2013.01); B82Y 30/00 (2013.01); C01P 2004/45 (2013.01); C01P 2006/12 (2013.01); C01P 2006/14 (2013.01)] 16 Claims
OG exemplary drawing
 
1. A method for forming a three-dimensional silicon-containing network comprising:
dispersing a cellulose nanocrystal template material in a reaction medium comprising water, such that the template material aggregates upon the dispersal to form a three-dimensional template within the reaction medium;
combining a tetraethyl orthosilicate silicon precursor, a cetyltrimethyl ammonium bromide surfactant, ethanol as a co-solvent, and a ammonium hydroxide catalyst in the reaction medium with the template, the reaction medium including the ethanol in an amount of 20 vol % of the reaction medium, and including the catalyst in a concentration of from 4 ml/L to 32 ml/L of the ethanol and the water of the reaction medium combined, wherein upon the combination the silicon precursor undergoes a sol-gel reaction and forms a silicon-containing gel on the three-dimensional template;
freeze drying the silicon-containing gel to form a silicon-containing layer on the three-dimensional template;
calcining or pyrolyzing the freeze-dried silicon-containing layer on the three-dimensional template and thereby removing or modifying the template; and
thermally reducing the silicon-containing layer to form the three-dimensional silicon-containing network, the network comprising a plurality of hollow nano-quills, each hollow nano-quill comprising silicon oxides and being defined by a hollow core surrounded by a porous wall, the three-dimensional network exhibiting multimodal porosity, wherein the multimodal porosity comprising large pores of 0.5 μm to 5 μm formed by interconnected arms of the nano-quills, and pores of the porous wall surrounding the hollow core having a dimension of 1 nm to 10 nm.