Abstract: The present application discloses an electrode assembly, compositions and batteries comprising the electrode assembly, uses of the electrode assembly and a method for producing the electrode assembly comprising the steps of: a. providing at least a first composite electrode material comprising at least one silicon layer on a current collector material; b. providing a welding material in contact with the composite material; and c. providing an electrode tab material in contact with the welding material, to form an aligned electrode assembly stack; and d. optionally, repeating steps a and/or b; and e. applying ultrasonic energy to a portion of the aligned electrode assembly stack to form: i. a weld material ii. a penetration weld through the electrode tab and the welding material and optionally through the composite material; and/or iii.

Abstract: The present application discloses an electrode assembly, compositions and batteries comprising the electrode assembly, uses of the electrode assembly and a method for producing the electrode assembly comprising the steps of: a. providing at least a first composite electrode material comprising at least one silicon layer on a current collector material; and b. providing an electrode tab material in contact with the current collector material, to form an aligned electrode assembly stack; c. optionally, providing a composite electrode material comprising at least one silicon layer on a current collector material in contact with the current collector material of another composite electrode, to form an aligned electrode assembly stack; d. optionally, repeating step c at least one time; and e. applying ultrasonic energy to a portion of the aligned electrode assembly stack to form: i. a weld material; ii. a penetration weld through the electrode tab and optionally through the composite material; and/or iii.

Abstract: The invention is related to a silicon composite material for use as a rechargeable battery anode, comprising (i) an electrically conductive substrate comprising a foil of copper or titanium, (ii) an adhesion layer attached to the foil comprising at least one or more metals and/or metal compounds and (iii) an electrode layer comprising silicon attached to the adhesion layer.