title: Low-cost carbon-silicon nanocomposite anodes for lithium ion batteries.
abstract: The specific energy of the existing lithium ion battery cells is limited because intercalation electrodes made of activated carbon (AC) materials have limited lithium ion storage capacities. Carbon nanotubes, graphene, and carbon nanofibers are the most sought alternatives to replace AC materials but their synthesis cost makes them highly prohibitive. Silicon has recently emerged as a strong candidate to replace existing graphite anodes due to its inherently large specific capacity and low working potential. However, pure silicon electrodes have shown poor mechanical integrity due to the dramatic expansion of the material during battery operation. This results in high irreversible capacity and short cycle life. We report on the synthesis and use of carbon and hybrid carbon-silicon nanostructures made by a simplified thermo-mechanical milling process to produce low-cost high-energy lithium ion battery anodes. Our work is based on an abundant, cost-effective, and easy-to-launch source of carbon soot having amorphous nature in combination with scrap silicon with crystalline nature. The carbon soot is transformed in situ into graphene and graphitic carbon during mechanical milling leading to superior elastic properties. Micro-Raman mapping shows a well-dispersed microstructure for both carbon and silicon. The fabricated composites are used for battery anodes, and the results are compared with commercial anodes from MTI Corporation. The anodes are integrated in batteries and tested; the results are compared to those seen in commercial batteries. For quick laboratory assessment, all electrochemical cells were fabricated under available environment conditions and they were tested at room temperature. Initial electrochemical analysis results on specific capacity, efficiency, and cyclability in comparison to currently available AC counterpart are promising to advance cost-effective commercial lithium ion battery technology. The electrochemical performance observed for carbon soot material is very interesting given the fact that its production cost is away cheaper than activated carbon. The cost of activated carbon is about $15/kg whereas the cost to manufacture carbon soot as a by-product from large-scale milling of abundant graphite is about $1/kg. Additionally, here, we propose a method that is environmentally friendly with strong potential for industrialization.
authors.affiliation: Center for Advanced Materials, University of Houston, Houston, TX 77204-5004, USA ; Department of Physics, College of Science, University of Tabuk, P.O. Box 741, Tabuk 71491, Kingdom of Saudi Arabia.
authors.forename: Nacer
authors.initials: N
authors.lastname: Badi
authors.affiliation: Center for Advanced Materials, University of Houston, Houston, TX 77204-5004, USA.
authors.forename: Abhinay Reddy
authors.initials: AR
authors.lastname: Erra
authors.affiliation: Center for Advanced Materials, University of Houston, Houston, TX 77204-5004, USA ; College of Engineering Technology, University of Houston, Houston, TX 77204-4020, USA.
authors.forename: Francisco C Robles
authors.initials: FC
authors.lastname: Hernandez
authors.affiliation: College of Engineering Technology, University of Houston, Houston, TX 77204-4020, USA.
authors.forename: Anderson O
authors.initials: AO
authors.lastname: Okonkwo
authors.affiliation: Department of Physics and Astronomy, University of Texas at Brownsville, Brownsville, TX 78520, USA.
authors.forename: Mkhitar
authors.initials: M
authors.lastname: Hobosyan
authors.affiliation: Department of Physics and Astronomy, University of Texas at Brownsville, Brownsville, TX 78520, USA.
authors.forename: Karen S
authors.initials: KS
authors.lastname: Martirosyan
keywords: Anode materials; Ball milling technique; Carbon-silicon nanocomposite; Electrochemical energy storage; Lithium ion batteries; Nanostructured carbon
references.citation: Nat Nanotechnol. 2008 Jan;3(1):31-5
references.pmid: 18654447
references.citation: ACS Nano. 2010 Aug 24;4(8):4806-14
references.pmid: 20731455
references.citation: Angew Chem Int Ed Engl. 2010 Mar 15;49(12):2146-9
references.pmid: 20175170
references.citation: Nat Nanotechnol. 2012 Mar 25;7(5):310-5
references.pmid: 22447161
references.citation: Nano Lett. 2010 May 12;10(5):1710-6
references.pmid: 20369889
references.citation: Nano Lett. 2009 Nov;9(11):3844-7
references.pmid: 19746961
references.citation: Nat Nanotechnol. 2009 Apr;4(4):217-24
references.pmid: 19350030
references.citation: Nat Nanotechnol. 2008 May;3(5):270-4
references.pmid: 18654522
references.citation: J Am Chem Soc. 2006 Jun 21;128(24):7720-1
references.pmid: 16771469
references.citation: Nano Lett. 2008 Nov;8(11):3688-91
references.pmid: 18950239
references.citation: ACS Nano. 2010 Jul 27;4(7):3671-8
references.pmid: 20518567