Improving cyclic performance of Si anode for lithium-ion batteries by forming an intermetallic skin

Abstract

An intermetallic NiSi x coating layer was introduced on the Si surface by sputtering Ni onto Si, followed by heat-treatment. The resulting chemically bonded NiSi x layer, unlike physically coated layers that typically can crack and detach from Si surfaces upon repeated cycling, remains connected with the bulk Si as a skin-like protective surface.