LiFePO4 is made of olivine, with the positive pole connected by aluminum foil. In between, there is a polymer diaphragm separating the positive and negative poles, allowing Li+ to pass through while E- cannot. The negative pole is made of carbon (graphite) and connected by copper foil. The battery has electrolyte between its top and bottom and is coated with metal, completely sealed. When LiFePO4 is charging, Li+ at the positive pole moves to the negative pole through the polymer diaphragm. During discharging, Li+ at the negative pole moves to the positive pole through the diaphragm. Li-ion batteries get their name from their back-and-forth motion during charging and discharging.