Development of Low-Cost Nano Cellulose Composite Electrolyte Membranes and Application Characteristics in Metal-Air Electrochemical Cells

We are all concerned about the problems from the serious global climate changes and the over-consumption in natural resources. In order to provide a sustainable environment for modern technology life, it is very important to develop high efficiency green energy materials and advanced electrical storage devices. This is essential to increase current power efficiency and renewable energy sources. There have been reported 3C battery explosions and even Tesla car battery burned due to an impact accident. A safer and more efficient energy storage system is highly desired. Lithium-air battery uses air cathode and can convert into lithium peroxide. The per-weight capacity can be nine times higher than a traditional battery. Therefore, our group will develop high energy density, low-cost nano-cellulose electrolyte metal-air (breathing) fuel cells. The high working voltage and low memory effects will be preserved. The fuel cell safety aspects and natural environment materials will be incorporated. We wish to open a new green energy era by the successful development of this new metal-air system. We will investigate natural cellulose materials for composite polymer electrolyte membranes. The new composite electrolyte membranes will be used in high energy density metal-air batteries, such as lithium-air, zinc-air, and aluminum-air. The cathode utilizes oxygen from ambient air as reactant in the electrochemical reaction rather than storing heavy active materials as in other battery systems. Lithium ion rechargeable battery is a remarkable energy storage system attributed to the excellent energy density and high working voltage. However, the safety is believed to be the most important issue to limit its use in 3C products or electric vehicles. However, poor ionic conductivity and low mechanical integrity still restrict the electrolyte separator from practical applications. We will improve the high temperature resistance of natural cellulose and polybutylene terephthalate polymer composite separators. The crosslinked cellulose materials are adapted to enhance the ionic conductivity to 10-3 S/cm vs Li+ and 10-2 S/cm vs OH- or H+. The thermal shrinkage, dimensional stability and safety, and thermal degradation activation energy ＞150 kJ/mol are also expected to be improved. In addition to the carbon porosity, the surface area and structure also affects the catalysis in the lithium-air battery system. The novel porous carbon electrode will be prepared and applied to the air electrode for the metal-air battery system. The main objective of this project is therefore to research and develop the novel natural nano-cellulose polymer composite electrolytes for the growing and challenging battery industry. The three year objectives are listed below.  First year: To design and prepare high temperature resistant, low-cost nano-cellulose based composite electrolyte membranes for metal-air batteries. To develop patent processes and to investigate metal-air battery electrochemical characteristics.  Second year: To further investigate metal-air fuel cell long term electrochemical characteristics, charge-discharge stability. To improve the nano-cellulose composite electrolyte membranes for optimization and lithium, zinc, aluminum- air battery electrochemical stability.  Third year: To integrate high conducting separators and optimized anodes/cathodes for the high energy density, high power lithium-air energy storage battery system, also transfer the technology.

Project ID:PB10901-0695
External Project ID:MOST108-2221-E182-020-MY3