A Novel and Generalized Lithium-Ion Battery Design for Enhanced Energy Density
Lithium-ion battery (LIB) is one of the most common electrochemical energy storage devices, and has been extensively investigated compared to other rechargeable battery systems. The traditional LIBs consist of several main components, including the cathode, the anode, the positive and negative current collectors, the electrolyte, and the separator. This basic battery configuration hasn’t changed since its appearance. The working mechanism of the conventional LIBs include lithium ions deintercalate from the cathode material, migrate through the electrolyte to intercalate into the anode material (i.e. graphite) during charging process, and discharging reverses the process. However, with the rapid development of portable devices and electric vehicles, due to the limited packaged energy densities, led to most traditional LIBs are unable to meet the high energy density demands of such applications.
Prof. TANG Yongbing and colleagues from the Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, recently developed a novel and generalized LIB configuration, which can increase the energy density of the battery by utilizing an Al foil anode in combination with conventional cathode materials, including LiCoO2, LiFePO4, and LiNi0.5Co0.2Mn0.3O2. In contrast to the conventional LIBs, the Al foil in this configuration acts as both the anode and current collector directly, thus conventional anode materials are omitted from the design. The working mechanism of the battery is different from conventional LIBs as well: during the charging process, lithium ions deintercalate from the LiCoO2 cathode and migrate to the Al foil anode to form an AlLi alloy. Conversely, in the discharge process, the lithium ions de-alloy from AlLi and migrate back to the LiCoO2 lattice.
Figure a. Traditional LIBs configuration; Figure b. Novel and generalized LIB configuration (Image by TANG Yongbing)
Owing to the elimination of conventional anode materials, the proportion of the electrode material in the total battery is larger, thus the energy densities of these batteries are dramatically improved. For the LiCoO2-Al battery, the energy density reaches up to 263 Wh/kg at a power density of 216 W/kg, which is about 1.5 times greater than a conventionalLiCoO2-based LIB. For the LiFePO4-Al battery, the energy density reaches up to 163 Wh/kg at a power density of 217 W/kg. For the LiNi0.5Co0.2Mn0.3O2-Al battery, the energy density reaches up to 258 Wh/kg at a power density of 275 W/kg. Additionally, the process for assembling this new battery design is simplified compared to typical LIBs, thus reducing production costs for making a promising candidate technology for the next-generation’s high-performance batteries.
At present, the cycling stability of the new battery still needs further improvement. Prof. TANG and colleagues believe that once the technique is commercialized, it will significantly enhance the performances of portable electronic devices, electric vehicles, and other renewable energy systems, etc.
This research was supported by the Guangdong Innovation Team and the National Natural Science Foundation of China, and have been published online entitled "A Novel and Generalized Lithium-Ion-Battery Configuration utilizing Al Foil as Both Anode and Current Collector for Enhanced Energy Density"
Shenzhen Institutes of Advanced