title: Assessing carbon-based anodes for lithium-ion batteries: a universal description of charge-transfer binding.
abstract: Many key performance characteristics of carbon-based lithium-ion battery anodes are largely determined by the strength of binding between lithium (Li) and sp(2) carbon (C), which can vary significantly with subtle changes in substrate structure, chemistry, and morphology. Here, we use density functional theory calculations to investigate the interactions of Li with a wide variety of sp(2) C substrates, including pristine, defective, and strained graphene, planar C clusters, nanotubes, C edges, and multilayer stacks. In almost all cases, we find a universal linear relation between the Li-C binding energy and the work required to fill previously unoccupied electronic states within the substrate. This suggests that Li capacity is predominantly determined by two key factors-namely, intrinsic quantum capacitance limitations and the absolute placement of the Fermi level. This simple descriptor allows for straightforward prediction of the Li-C binding energy and related battery characteristics in candidate C materials based solely on the substrate electronic structure. It further suggests specific guidelines for designing more effective C-based anodes. The method should be broadly applicable to charge-transfer adsorption on planar substrates, and provides a phenomenological connection to established principles in supercapacitor and catalyst design.
authors: Quantum Simulations Group, Lawrence Livermore National Laboratory, Livermore, California 94550, USA and Department of Materials Science and NanoEngineering, Department of Chemistry, and the Smalley Institute for Nanoscale Science and Technology, Rice University, Houston, Texas 77005, USA.
authors: Yuanyue
authors: Y
authors: Liu
authors: Nanoscale Synthesis & Characterization Laboratory, Lawrence Livermore National Laboratory, Livermore, California 94550, USA.
authors: Y Morris
authors: YM
authors: Wang
authors: Department of Materials Science and NanoEngineering, Department of Chemistry, and the Smalley Institute for Nanoscale Science and Technology, Rice University, Houston, Texas 77005, USA.
authors: Boris I
authors: BI
authors: Yakobson
authors: Quantum Simulations Group, Lawrence Livermore National Laboratory, Livermore, California 94550, USA.
authors: Brandon C
authors: BC
authors: Wood