Yttrium-doped and conductive polymer-coated high nickel layered cathode material with enhanced structural stability

Abstract

In this study, high nickel layered LiNi0.8Co0.1Mn0.1O2 cathode materials for lithium-ion batteries were modified by yttrium doping and poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) coating. The effects of yttrium doping and PEDOT:PSS coating on the structural and electrochemical properties of the LiNi0.8Co0.1Mn0.1O2 cathode material were investigated and compared. The substitution of nickel with an electrochemically inert yttrium was confirmed to be successful in stabilizing the layered structure framework. Moreover, coating the surfaces of the LiNi0.8Co0.1Mn0.1O2 particles with a conductive polymer, PEDOT:PSS, improved the capacity retention, thermal stability, and impedance of the cathode material by increasing its ionic and electric conductivities.