Electrolyte Capable of Dramatically Increasing the Energy Efficiency and Life of Lithium-Air Batteries
National Institute for Materials Science(NIMS)
A NIMS research team developed a novel electrolyte demonstrated to dramatically increase the energy efficiency and life of lithium-air batteries.
(“Highly Efficient Br
–/NO
3– Dual-Anion Electrolyte for Suppressing Charging Instabilities of Li–O
2 Batteries”; Xing Xin ,
Kimihiko Ito, and
Yoshimi Kubo; ACS Appl. Mater. Interfaces, 2017, 9 (31), pp 25976–25984, DOI:
10.1021/acsami.7b05692)
Abstract
- A NIMS research team led by Team Leader Yoshimi Kubo, Postdoctoral Researcher Xing Xin and Principal Researcher Kimihiko Ito (Lithium Air Battery Specially Promoted Research Team, Global Research Center for Environment and Energy based on Nanomaterials Science) developed a novel electrolyte demonstrated to dramatically increase the energy efficiency and life of lithium-air batteries.
- Demand for rechargeable batteries (secondary batteries) is expected to rapidly increase due to the increasing popularity of electric vehicles and household storage of electricity generated by solar cells. Lithium-air batteries are theoretically capable of storing the highest energy densities, and are considered the “ultimate” rechargeable batteries. Lithium-ion batteries are currently the most widely used rechargeable batteries, but their energy density, which represents their electricity storage capacity, has nearly reached its limits. Lithium-air batteries are potentially capable of much higher storage capacities and much lower production costs. However, these batteries have major issues—their energy efficiency is low because their charge voltage is higher than their discharge voltage and their lithium metal anodes are short-lived.
- The research team recently developed a novel electrolyte capable of considerably increasing the energy efficiency and life of lithium-air batteries. The use of this electrolyte reduced the excessive voltage that needed to be applied to the battery’s cathode (overpotential) during charging by more than 50% (from the conventional average of 1.6 V or higher to approximately 0.6 V). In addition, the energy efficiency of the battery was greatly increased, from approximately 60% to 77%. We were also able to more than double the number of lifetime charge-discharge cycles of the battery from the conventional average of 20 cycles or fewer to over 50 by preventing lithium metal dendrite growth, which is considered to be a battery life reducing factor.
- Based on these results, we hope to achieve the practical introduction of large-capacity, long-life lithium-air rechargeable batteries for use in electric vehicles and households in the near future.
- This research project was funded by the MEXT-commissioned “Program for the Development of Environmental Technology Using Nanotechnology” (until FY2015), the “Program for Integrated Materials Development” (from FY2016) and JST’s ALCA-SPRING program.
- This study was published in the online edition of ACS Applied Materials & Interfaces on July 17, 2017, local time.
Cross-sections of lithium metal anodes after batteries were subjected to cycle tests. (a) Conventional and (b) newly developed electrolytes
