How convenient would it be if we could use smartphone batteries longer and more safely? A research team led by Professor Moon Jeong Park at POSTECH (Pohang University of Science and Technology) has announced an innovative research outcome that could turn this vision into reality, gaining significant attention from both academia and the public. In particular, this study builds upon their previous research published in Science last year, where they introduced the “plumber’s nightmare” structure to maximize lithium-ion battery performance, making it even more meaningful.
Lithium-ion batteries are broadly used in modern technologies, including smartphones. While the electrolyte is one of the core components of a battery, conventional liquid electrolytes have risks of leakage or explosion. Solid-state electrolytes are emerging as an alternative, but there have been limitations in balancing the electrolyte’s ‘mechanical strength’ and ‘ionic conductivity’.
A research team led by Professor Park Moon Jeong, Dr. Kim Ji-hoon, and doctoral student Lee Ho-joon from the Department of Chemistry at POSTECH has presented an innovative method that dramatically improves both the ionic conductivity and mechanical properties of batteries by adding only a tiny amount of lithium salt – less than one-tenth the level used in conventional electrolyte production that used more than a few mole concentration of lithium salt to increase ionic conductivity.
The key to this approach is that adding a very small amount of lithium salt to the PS-b-PEO1) block copolymer2) selectively locates it at the terminal hydroxy groups (-OH) of the PEO chain. Through this, the research team succeeded in forming a sophisticated “plumber’s nightmare” structure unobserved in conventional polymer electrolyte systems.
The “plumber’s nightmare” structure refers to an arrangement where all polymer chain ends are entangled inward, just like plumbing pipes gather internally. This structure has six channels formed by the polymer chains, all connected. The structure provides a stable ion pathway as the lithium ions are locally present in the hydroxy groups at the center of the polymer channels. As a result, it creates an environment where ions can move quickly and efficiently while maintaining the hard and robust structure of the electrolyte.
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