Nickel-rich layered oxides are currently considered the most practical candidates for realizing high-energy-density lithium metal batteries (LMBs) because of their relatively high capacities. However, undesired nickel-rich cathode–electrolyte interactions hinder their applicability. Here, we report a satisfactory combination of an antioxidant fluorinated ether solvent and an ionic additive that can form a stable, robust interfacial structure on the nickel-rich cathode in ether-based electrolytes. The fluorinated ether 1,1,2,2-tetrafluoroethyl-1H,1H,5H-octafluoropentyl ether (TFOFE) introduced as a cosolvent into ether-based electrolytes stabilizes the electrolytes against oxidation at the LiNi0.8Mn0.1Co0.1O2 (NCM811) cathode while simultaneously preserving the electrochemical performance of the Li metal anode. Lithium difluoro­(bisoxalato)­phosphate (LiDFBP) forms a uniform cathode–electrolyte interphase that limits the generation of microcracks inside secondary particles and undesired dissolution of transition metal ions such as nickel, cobalt, and manganese from the cathode into the electrolyte. Using TFOFE and LiDFBP in ether-based electrolytes provides an excellent capacity retention of 94.5% in a Li|NCM811 cell after 100 cycles and enables the delivery of significantly increased capacity at high charge and discharge rates by manipulating the interfaces of both electrodes. This research provides insights into advancing electrolyte technologies to resolve the interfacial instability of nickel-rich cathodes in LMBs.

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Here, we report the first electrochemical assessment of organophosphonate-based compound as a safe electrode material for lithium-ion batteries, which highlights the reversible redox activity and inherent flame retarding property. Dinickel 1,4-benzenediphosphonate delivers a high reversible capacity of 585 mA h g with stable cycle performance. It expands the scope of organic batteries, which have been mainly dominated by the organic carbonyl family to date. The redox chemistry is elucidated by X-ray absorption spectroscopy and solid-state P NMR investigations. Differential scanning calorimetry profiles of the lithiated electrode material exhibit suppressed heat release, delayed onset temperature, and endothermic behavior in the elevated temperature zone.

속도론적인 관점에서 실험변수를 조절하여 얻어진 결과로부터 침강성 탄산칼슘(precipitated calcium carbonate, PCC)의 생성을 핵 생성속도로 규명하였다. 반응온도 80 o C에서 Ca(OH) 2 slurry, Na 2 CO 3 수용액 및 다양한 농도의 NaOH를 첨가하여 침강성 탄산칼슘 의 생성거동을 관찰하였다. 핵생성속도는 주 반응물인 Ca 2+ 이온과 CO 3 2-용해속도를 조건으로 나누어 진행하였다. 두 이온의 농도 가 고농도일경우에는 vaterite와 calcite가 혼재되어 나타났다. Ca 2+ 이온과 CO 3 2-이온농도 중 어느 하나만을 낮게 하여 반응시킨 경 우에는 주로 calcite가 생성되었으며 두 이온농도가 모두 낮을 경우에는 aragonite가 형성되었다. 또한 NaOH 농도를 증가시킴에 따 라 calcite의 생성은 감소하였으며 5M NaOH 수용액 내에서 단일상의 aragonite를 얻을 수 있었다. 따라서 본 연구에서는 과포화도 조절을 통해 다형체(polymorphs) 중 특정 형태를 합성할 수 있었다.