A joint research team led by Professor Soojin Park (CHEM), Sangyeop Lee (Integrated Candidate, AMS), Dr. Sungjin Cho (CHEM), Hyunbeen Choi (Combined MS/PhD program Candidate, CHEM), and Dr. Jin Hong Kim and Dr. Hongyeul Bae of POSCO Holdings N.EX.T Hub has recently succeeded in enhancing performance and durability of “All-Solid-State battery.” The research has been published in the international academic journal Small.
Secondary batteries generally use liquid electrolyte that are inflammable, entailing fire hazards. Therefore, the replacement of liquid electrolytes with solid electrolytes and lithium ions for all-solid-state batteries is actively being researched.
All-solid-state batteries generate electricity using lithium plated on the cathode and the transfer of electrons. When the battery is charged or discharged, lithium metal either loses electrons and becomes ionized, or gains electrons and deposits in the form of metal. If lithium deposits in a non-uniform manner during this process, the capacity of lithium depletes rapidly, and hence the performance and durability of the battery strikingly decline.
In an attempt to resolve this issue, the research team produced a functional binder-based cathode protective layer for all-solid-state batteries. This layer excels in transferring lithium, and induces “bottom electrodeposition,” a state in which lithium is uniformly deposited from the bottom of the cathode surface.
Scanning electron microscope (SEM) analysis also showed stability of the transfer of lithium-ion with this layer. As a consequence, unnecessary consumption of lithium decreased prominently, and even a thin layer of lithium metal, less than 10μm in thickness, enabled long duration of battery use.
Prof. Park emphasized the introduction of bottom electrodeposition and showed hopes to “present a new guidance to enhance the durability of the battery and energy density” in future research. POSCO Holdings plans to commercialize lithium metal cation, a key material for next-generation secondary batteries, based on this joint research outcome.
The research was supported by POSCO Holdings, Ministry of Trade, Industry, and Energy (MOTIE), and Korea Planning & Evaluation Institute of Industrial Technology (KEIT).
