ANODES WITH MESOPOROUS SILICON PARTICLES
The present invention provides anode materials, methods of producing them, electrochemical cells, and lithium-ion batteries, where the anode material comprises mesoporous silicon and carboxymethyl cellulose. In certain embodiments, the mesoporous silica additionally comprises other materials within its pores, such as lithium.
1 . An anode material comprising:
mesoporous silicon particles having an average pore diameter from about 1 nm to about 500 nm; and
carboxymethyl cellulose (CMC).
2 . The anode material of claim 1 , wherein the mesoporous silicon particle has a particle diameter of from about 50 nm to about 250 nm.
3 . The anode material of claim 1 , wherein the mesoporous silicon particle has a particle diameter from about 80 nm to about 150 nm.
4 . The anode material of claim 1 , wherein the mesoporous silicon particles comprise lithium in the pores.
5 . The anode material of claim 1 , further comprising styrene-butadiene rubber (SBR).
6 . A method for preparing the anode material of claim 1 , comprising:
contacting a silicon tetrahalide with a reducing agent under conditions sufficient to form a reduced silicon;
contacting the reduced silicon with an alkylating agent or an alkoxide to form an alkyl-capped silicon gel;
annealing a mixture of the alkyl-capped silicon gel and a template to form a mesoporous silicon particle having an average pore diameter from about 1 nm to about 500 nm; and
mixing the mesoporous silicon particle with carboxymethyl cellulose (CMC), thereby preparing the anode material of claim 1 .
7 . The method of claim 6 , wherein the silicon tetrahalide is silicon tetrachloride.
8 . The method of claim 6 , wherein the reducing agent is sodium naphthalide.
9 . The method of claim 6 , wherein the alkylating agent is alkyl lithium.
10 . The method of claim 6 , wherein the alkylating agent comprises a C 1-6 alkyl group.
11 . The method of claim 6 , wherein the template is a nanoparticle silica template.
12 . The method of claim 6 , further comprising heating the alkyl-capped silicon gel to remove the reducing agent.
13 . The method of claim 6 , further comprising before the mixing step, removing the template.
14 . The method of claim 6 , further comprising before the mixing step, depositing lithium in the pore to form a lithiated mesoporous silicon particle.
15 . The method of claim 14 , wherein the depositing is performed via chemical vapor deposition (CVD).
16 . An anode material prepared by the method of claim 6 .
17 . An anode material prepared by the method of claim 14 .
18 . A Li-ion battery comprising the anode material of claim 1 .
19 . Use of mesoporous silicon particles and carboxymethyl cellulose for an anode material, wherein the silicon particles have an average pore diameter from about 1 nm to about 500 nm.