TAGS: Automotive New Energy Solutions
Toray Industries, Inc., announced that it has developed an ion-conductive polymer membrane that delivers 10-fold the ion conductivity of predecessors. This new offering could accelerate the deployment of solid-state batteries, air batteries, and other lithium metal batteries, greatly expanding the cruising ranges of electric vehicles, industrial drones, urban air mobility systems, and other transportation modes.
Offers Ion Conductivity through Hopping Conduction
The transition to electric mobility is increasing the demand for lithium-ion batteries with higher energy densities. As a result, efforts are underway to develop lithium metal batteries with anodes that allow for the highest theoretical energy capacity.
The challenge of lithium metal is its high surface reactivity and the stability issues associated with its dissolution and precipitation morphology during charging and discharging cycles. One notable drawback is the growth of lithium dendrites, which can cause short circuits. Metallic lithium anodes in batteries employing solid electrolytes pose similar hurdles, and have yet to see practical applications.
Toray developed polymer membranes offering ion conductivity through hopping conduction. This mechanism enables lithium ions to traverse between interacting sites within polymer membranes, effectively jumping across sites. The membranes remain non-porous. This breakthrough leveraged the company’s expertise in molecular design technology, particularly with aramid polymers, which it refined over many years.
Toray estimates that enhancing the hopping site structure and designing a new polymer with more hopping sites has delivered the highest ionic conductivity in the 10-4 S/cm range for a hopping-conductive polymer film.
Acts as a Protective Film to Overcome Challenges of Lithium Metal
Toray confirmed that the polymer film effectively functions as a protective film on lithium metal surfaces to overcome the issues mentioned earlier, and should extend the service lives of batteries using lithium metal lithium anodes.
Joint research with professor Nobuyuki Imanishi of the Graduate School of Engineering at Mie University verified the achievement of 100 charge-discharge cycles for the first time in a dual-component lithium-air battery using this polymer membrane as a separator.
Toray will accelerate research to rapidly establish the technology for use in solid-state, air, and other advanced batteries.
Part of the development work for the new membrane was through a project funded by the New Energy and Industrial Technology Development Organization (NEDO). Toray presented its technology at the 91
st Annual Meeting of the Electrochemical Society of Japan, which was held from March 14-16 this year.
Toray will keep leveraging its core technologies of synthetic organic and polymer chemistry, biotechnology, and nanotechnology to innovate materials in keeping with its commitment to delivering new value and contributing to social progress.
Source: Toray
