リチウムイオン電池とは?

  • 1 リチウムイオン二次電池のメカニズム
  • 2 リチウムイオン二次電池ができるまで
これからのスタンダード リチウムイオン電池

リチウムイオン二次電池のメカニズム

リチウムイオン電池の原理なぜ充電と放電を繰り返せるのか

リチウムイオン電池の原理

Lithium-ion batteries typically use a lithium metal oxide in the cathode and a carbon-based material in the anode.

When the batteries are charging, electrons move from the cathode to the anode, and lithium ions move from the cathode and into the carbon-based material of the anode. If the cathode and the anode are connected in this state, lithium ions flow from the anode and return to the cathode, and the electrons travel through the connection to the cathode and combine with the lithium ions. When this occurs, an electric current is generated from the cathode to the anode.

リチウムイオン電池の特徴他の電池と比べたリチウムイオン電池の優位性

Most of battery key performances (energy density, power density, voltage etc.) are determined by chemistry of cathode and anode. The combination of Li-based anode and Li oxide with transitionmetal is the best to achieve higher operational voltage.

電圧が高い Ni-Cd,Ni水素の3直列 = Liイオン

エネルギー密度が高い

Comparing voltages, a lead-acid battery used in vehicle has 2V with a combination of lead dioxide in the cathode and lead in the anode. (Vehicle 12V batteries are configulated by connecting 6 of 2V batteryl in a series.) Nickel Cadmium battery (Ni-Cd) has 1.2V using a combination of Nickel oxyhydroxide in the cathode and cadmium in the anode. And Nickel-metal hydride battery (Ni-MH) has 1.2V using a combination of the cathode with Nickel oxyhydroxide and the anode with hydrogen storage alloy.

In contrast, voltage of lithium-ion battery can be obtained in range of 3.2~3.8V by the combination Li transition metal oxide in cathode and Li-based carbon in anode, which means that the voltage is 3 times higher than that of Ni-Cd and Ni-MH.

In addition, the energy density of lithium-ion battery is also superior with enegy densities that are more than 2 times of Ni-MH. Therefore, if the batteries are of the same capacity, Li-ion battery can achieve "half" battery volume and "half" battey weight of Ni-MH for itself.

2 リチウムイオン二次電池ができるまで