Haek-Joon Park

This progress report reviews the most recent discoveries regarding Li–O₂chemistry during each discharge and charge process.

Abstract Co-intercalation reactions make graphite as promising anodes for sodium ion batteries, however, the high redox potentials significantly lower the energy density. Herein, we investigate the factors that influence the co-intercalation potential of graphite and find that the tuning of the voltage as large as 0.38 V is achievable by adjusting the relative stability of ternary graphite intercalation compounds and the solvent activity in electrolytes. The feasibility of graphite anode in sodi

Recent discovery of high-concentration electrolyte systems has opened a new avenue toward the high-voltage, safe, and low-cost aqueous rechargeable batteries. However, the need for generally high-cost organic solutes in the high-concentration electrolyte has become another major obstacle. Herein, we revisited all the commonly used low-cost solutes for high-concentration system and discovered that the use of NaClO4 solute effectively results in a wide electrochemical stability window by suppressi

We report that the self-discharge of lithium-ion batteries can be abnormally accelerated when thermal ‘history’ is memorized as the form of an internal ‘parasitic’ lithium source.

Abstract The rampant generation of lithium hydroxide and carbonate impurities, commonly known as residual lithium, is a practical obstacle to the mass‐scale synthesis and handling of high‐nickel (>90 %) layered oxides and their use as high‐energy‐density cathodes for lithium‐ion batteries. Herein, we suggest a simple in situ method to control the residual lithium chemistry of a high‐nickel lithium layered oxide, Li(Ni 0.91 Co 0.06 Mn 0.03 )O 2 (NCM9163), with minimal side effects. Based on th

Abstract Cobalt‐free layered lithium‐rich nickel manganese oxides, Li[Li x Ni y Mn 1− x − y ]O 2 (LLNMO), are promising positive electrode materials for lithium rechargeable batteries because of their high energy density and low materials cost. However, substantial voltage decay is inevitable upon electrochemical cycling, which makes this class of materials less practical. It has been proposed that undesirable voltage decay is linked to irreversible structural rearrangement involving irreversibl

Shedding new light on conventional batteries sometimes inspires a chemistry adoptable for rechargeable batteries. Recently, the primary lithium-sulfur dioxide battery, which offers a high energy density and long shelf-life, is successfully renewed as a promising rechargeable system exhibiting small polarization and good reversibility. Here, we demonstrate for the first time that reversible operation of the lithium-sulfur dioxide battery is also possible by exploiting conventional carbonate-based

Magnesium (Mg) rechargeable batteries are one of the promising high-energy post-lithium battery chemistries exploiting the multivalent charge carrier. However, the use of magnesium metal has been challenging due to the formation of the ion-blocking passivation layer on magnesium metal in most organic electrolytes. Herein, we propose a new strategy to transform the passivating film into a Mg2+-conductive interphase via simple chemisorption of sulfur dioxide molecules on magnesium metal. The facil

Abstract Lithium metal batteries (LMBs) are one of the most promising next‐generation batteries in achieving the high energy density because of their low reduction potential and large theoretical capacity. However, since the birth of the first rechargeable lithium batteries, the uncontrolled lithium growth and the accompanying side‐reactions have seriously hampered the development of LMBs. Decades of research efforts have extensively studied the mechanisms governing these issues; however, the pr

Lithium-rich layered oxides (LLOs) have attracted tremendous attention as promising next generation cathode materials thanks to their superb capacity through additional anionic oxygen redox and lower cost by less use of expensive transition metals.

Abstract Ni‐rich layered oxides are envisioned as the most promising cathode materials for next‐generation lithium‐ion batteries; however, their practical adoption is plagued by fast capacity decay originating from chemo‐mechanical degradation. The intrinsic chemical–mechanical instability, inherited from atomic‐ and nanoscale defects generated during synthesis, is not yet resolved. Here, atomic‐ and nanoscale structural evolution during solid‐state synthesis of Ni‐rich layered cathode, Li[Ni 0.