Anion effect on Li/Na/K hybrid electrolytes for Graphite//NCA(LiNi0.8Co0.15Al0.05O2) Li-ion batteries

• 作者: Aiman Jrondi Georgios Nikiforidis Mérièm Anouti
• 来源期刊: 能源化学
• 年，卷（期）: 2022,（1）
• 页码范围: 451-462
• 页数: 12页
• 语种: 英文

摘要

The electrolyte is an essential component of a battery system since it is responsible for the conduction of ions between the electrodes.In the quest for cheaper alternatives to common organic electrolytes for lithium-ion batteries (LIB),we formulated hybrid electrolytes comprising a mixture of Na,K,and Li alka-line salts with ethylene carbonate (EC),ethyl methyl carbonate (EMC),and lithium hexafluorophosphate(LiPF6),giving a total salt concentration of 1.5 M;we determined their physicochemical properties and investigated their electrochemical behavior on a nickel cobalt aluminum oxide (NCA) cathode and gra-phite (Gr) anode.The electrolytes demonstrated a melting transition peak (Tm),eutectic behavior,and ionic conductivities (～13 mS cm-1) close to those of a commercial LIB electrolyte (SE,EC/EMC + 1 M LiPF6) and activation energies of ca.3 kJ mol-1.The half-cell coin cells revealed high coulombic efficiency(99％),specific capacity (175 mAh g-1 at C/10),and capacity retention (92％ for NaCF3SO3) for the NC.A cathode and a moderate performance (coulombic efficiency of 98％ for 20 cycles) on the graphite anode after the formation of the SEI layer.The hybrid electrolytes were cycled at 25 ℃ in a Gr//NCA cell yielding specific capacities of ca.225 mAh g-1 at a C/5 rate,corroborating that the anion plays a key role and high-lighting their potential for energy storage applications.