An apparatus includes a presenting unit and a control unit. The 9–9H-fluorene compound include octyl-9–9H-fluorene-9-carboxylate; 7-methyloctyl-9–9H-fluorene-9-carboxylate; 2-ethylhexyl-9–9H-fluorene-9-carboxylate; and 9–9H-fluorene-9-yl benzoate. A crystalline lithium metal oxide film may be used as the cathode film 18.