Provided is a method of unevenly distributing a specific element in a copper phase out of platinum group elements that exist in the copper phase, including further adding copper into a molten copper phase containing the platinum group elements including at least rhodium, thereby increasing a distribution ratio of rhodium in the molten copper phase. The composition may further include a carrier medium, such as fructo-oligo-saccharides, as incorporated in a dose form such as a pill, capsule, powder or sachet. The selector circuit is further configured to permit parallel operation of two or more of the batteries.