The process of energy transfer between electric vehicle and power grid end is widely studied. Based on CLLC bi-directional DC-DC converter used in electric vehicle, a super capacitor staggered parallel current-doubling energy storage and discharge circuit is added to the electric vehicle end. A novel efficient bi-directional DC-DC converter is proposed. The forward and reverse operation processes of the novel DC-DC converter are analyzed, and the gain characteristics are studied. The conditions for realizing zero voltage switching (ZVS) of switch tube are put forward, and the electrical stress of switch tube is analyzed. An 800 W experimental prototype is made. Test results of the prototype prove that ZVS can be realized in the novel bi-directional DC-DC converter. The peak current of the switch tube is small, and the efficiency of the DC-DC converter is improved.