Pulsed plasma induced protection coatings on composite LiMn2O4 powder cathodes

A low temperature direct current pulsed plasma technique has been applied on laminated composite lithium manganese oxide powder cathodes containing the polyvinylidene fluoride binder and carbon black additive. The plasma treatment results in mass transport on the surface of the particles due to an ion bombardment induced atomic peening process. A thin layer is induced on the particle surface. This plasma induced surface layer acts as a protection coating, which improves the cycling and structural stability of the treated cathodes even at high discharge rates, high temperature (60 °C) and low cut-off potential (2.0 V). The X-ray photo electron spectra of Mn3p for the treated and untreated samples after high temperature (60 °C) cycling reveal binding energy shift on the surface of the untreated sample, whereas a stable molecular structure is preserved in the pulsed plasma treated cathode.