Plastic crystal embedded elastomer electrolyte (PCEE) via polymerization-induced phase separation (PIPS) was developed for lithium metal batteries.
Lithium metal batteries (LMBs) have emerged as a promising alternative to conventional Li ion batteries due to their higher energy density. Solid-state electrolytes are a key technology for the safe operation of lithium metal batteries. Especially, solid polymer electrolytes (SPEs) are a strong candidate for solid-state LMBs, with their advantages such as high flexibility, light-weight, and easy processability. However, SPEs usually have limitations, such as low ionic conductivity and insufficient mechanical properties to suppress the growth of lithium dendrites during cycling. Therefore, we developed PCEE showing the bicontinuous structure of plastic crystal phase and elastomer phase via PIPS. This bicontinuous structure allows for independent optimization of each phase to achieve superior ionic conductivity of plastic crystal and mechanical properties of elastomer simultaneously. Based on this advatnages, we design the PCEE with manipulating each phase respectively (e.g. phase ratio, monomer structure). We anticipate that the synergistic effects of the bicontinuous structure enable the superior performance of SPE-LMBs.
Block copolymer (BCP)-based mesoporous carbon particle systems were developed for various energy applications: cathode materials for highly durable fuel cell and anode materials for high performance battery.
The increasing demand and fast expansion of electric vehicle market urges developing proton exchange membrane fuel cell (PEMFC) and next generation battery. One major component of a typical PEMFC is the Pt catalysts loaded on the cathode, where the oxygen reduction reaction (ORR) occurs. Due to the sluggish reaction kinetics of the ORR, a massive amount of Pt is required, hindering the expansion of the PEMFC market. Therefore, we have developed BCP-based mesoporous carbon particle with an ultra-small amount of Pt. This particle shows exceptionally high mass activity and durability in single cell test. Furthermore, these mesoporous particles exhibit versatility as a 3D hierarchical host, suitable for applications in anode-free sodium-metal batteries and high-performance zinc metal anodes. The study focuses on manipulating the structures of the carbon host to effectively tackle challenges associated with dendrite growth, a prevalent issue impacting the performance of zinc batteries. Additionally, the optimization of metal atom coordination is emphasized as a means to attain high performance in zinc-based battery systems, leveraging the inherent zincophilicity of the designed structures.
Experimental platform for generating uniform BCP particles with controlled size, shape, and internal structures were developed.
The self-assembly of BCPs in 3D confinement has attracted great attention due to their unique internal morphologies and various potential applications. The self-assembly of polymers inside the emulsion droplets is generated by the solvent evaporation of polymer solution followed by the nucleation of polymer structures associated with bending/stretching of polymer chains, which leads to solid polymer particles with ordered internal structures. We have developed the Shirasu Porous Glass (SPG) membrane emulsification technique to achieve a narrow size distribution of BCP particles. Not only the size but also the shape (i.e. aspect ratio) of particles can be systematically controlled, and this technique is highly advantageous to practical applications of these particles. Moreover, the combination of BCPs and nanoparticles (NPs) has enabled the creation of flexible composites with favorable optical, electrical, magnetic, and mechanical properties. Our study delves into the formation mechanism of BCP/NP hybrid particles, showcasing hierarchical nanostructures achieved through 3D confined assembly. This practical research system has been employed to design advanced nanostructures and hybrid materials tailored for specific functions.
Reversible color and shape transformation of and BCP particles in response to external stimuli, such as temperature, pH, and light, were achieved.
Shape-transformable particles response to external stimuli are highly promising smart materials due to their switchable optical properties, rheological behavior, and cellular interactions. We have developed the shape-transforming polymer particle system by combining BCP self-assembly in 3D confinement with stimuli-responsive components. In this aspect, we have developed a simple and effective method for producing anisotropic BCP particles by utilizing stimuli-responsive surfactants that lead to the reversible shape and morphological transitions in response to external triggers. Additionally, we have designed multifunctional BCPs based on polymers responsive to various stimuli such as temperature, pH, light, gas, etc. Moreover, we have created functional hydrogel displays that shows the reversible patterning capability response to specific wavelength of light.
