A negative electrode for a lithium secondary battery of the present invention includes a negative active material including a plate-shaped carbon powder particle agglomerated in a primary structure in which the plate-shaped particle is oriented in a plane direction and laminated. The invention also relates to a process for producing a layer of amorphous hafnium oxide on a substrate, characterised in that the deposit is carried out without energy input to the substrate. The compounds are suitable for example as medicaments for the prevention and treatment of type 2 diabetes.