A method for forming a high aspect ratio sintered powder anode with low warpage, an anode made thereby and a cathode comprising the anode are provided. The method comprises placing a multiplicity of anode precursors on a forming substrate in a common plane wherein no more than 10% of the anode precursors are out of the common plane. A second substrate is then placed over the forming substrate with the anode precursors between the forming substrate and the second substrate thereby forming a sandwiched assembly. The sandwiched assembly is heated to a sintering temperature of the anode precursors thereby forming the sintered powder anodes. The and sintered powder anodes are removed from between the forming substrate and the second substrate.