Solid-Binding Peptides as a Biotemplate for Li-Ion Battery Electrodes

Abstract

Li-ion battery electrodes composed of electroactive materials at the nanoscale level show higher capacity and energy density over macroscale structures. However, nanoscale battery materials are prone to aggregation upon cell cycling, which reduces the specific capacity and coulombic efficiency, thus, leading to poor cycling stability. Using a biotemplating approach for electrode fabrication presents opportunities that may overcome aggregation and improve conductivity through introduction of biological nanoscale templates that would precisely control the position of electroactive nanoparticles in intimate proximity with conductive material and provide structural support upon cycling. Engineering of nanoscale bridges between electroactive and conductive material is done using solid-binding peptides (SBP) that have specific binding affinity for the materials of interest. In our study, SBP for cathode material Li2Mn3NiO8 (LMNO) was isolated using M13 bacteriophage through Phage Display procedure (New England Biolabs®). The nature of binding affinity between the peptide and the active material was determined through site-directed mutagenesis of specific amino acids in the peptide sequence. Binding peptides for LMNO and multiwalled carbon nanotubes (MWCNTs) are combined to form bifunctional peptide that serve as a nanobridge to connect two materials with synergistic properties. In this presentation I will discuss research on determining how SBPs bind to electroactive materials, and I will also show the impact that multifunctional SBPs have on improving battery electrode performance.