The working principle of lithium-ion battery is refers to the principle of charging and discharging. When charging the battery, the battery has lithium ions generated in the anode, the generated lithium ions through the electrolyte to the negative movement. As a cathode carbon layer structure, it has many pores, arrived in the cathode of lithium ion is embedded into the microporous carbon layer, the embedded lithium ion, the more the higher the charge capacity. Likewise, when to discharge the battery (i.e., we use the battery process), embedded in the cathode carbon layer of emergence, lithium ions and movement back to the anode. Back to the anode of lithium ion, the more the higher the discharge capacity. We usually mean by battery capacity is the discharge capacity. It is not hard to see, in the process of charging and discharging lithium ion batteries, lithium ion in the motion state from the positive and negative to the anode. If we compared the image of the lithium ion battery as a rocking chair, rocking chair at both ends of the poles for the battery, and lithium ion as excellent athlete, at opposite ends of the rocking chair