Cognitive radio is an intelligent radio which can be programmed and configured dynamically. It is widely used in spectrum sensing, spectrum sharing, environment sensing, etc. In this paper, we employ cognitive radio to harvest energy during packet transmissions using energy techniques. Energy harvesting involves two cooperation nodes: Energy cooperation mode and joint cooperation mode. In each cooperation mode, a pair of Primary Users(PUs), a pair of Secondary Users(SUs), and a cognitive radio network are used. In energy cooperation mode, secondary users transmit their own packets by harvesting energy from the primary transmission. In joint cooperation mode, Secondary users act as a relay for primary packets by using the energy harvested from the primary transmission. Further, we obtain maximum throughput by achieving a balance between energy harvesting and packet transmission.