Borate-Functionalized Disiloxane as Effective Electrolyte Additive for 4.5 V LiNi_0.8Co_0.1Mn_0.1O₂/Graphite Batteries

Abstract

Ni-rich LiNi 0.8 Co 0.1 Mn 0.1 O 2 (NCM811) is considered the most prominent cathode material to establish a practical high energy density of lithiumion batteries (LIBs) for future electric vehicles. The energy density of LIBs is greatly determined by the capacity of electrode materials and the operating voltage of the cells. To further improve the cycle lifespan of NCM811 batteries to meet the requirement of driving range for the electric vehicle market, it is vital to design a novel electrolyte additive that can enhance the stability of the cathode/ electrolyte interface at a wide range of voltage. Herein, a novel borate functionalized disiloxane compound, 1,1,1,3,3-pentamethyl-3-(3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)propyl) disiloxane (PMBPDS), is synthesized as cathode electrolyte interphase (CEI) film-forming additive to improve the cycling performance of NCM811 batteries. Systematic studies reveal that PMBPDS can construct a stable CEI film on the NCM811 surface and efficiently scavenge hydrofluoric acid (HF). The PMBPDS-derived CEI prevents the dissolution of transmission metals in the NCM811 cathode and enhances the capacity retention of NCM811/graphite cells from 68.3 to 70.6% after 200 cycles at 1 C in the voltage window of 3−4.5 V. This work provides more understanding on designing the molecular structure of additive compounds for improving the electrochemical performance of LIBs. KEYWORDS: LiNi 0.8 Co 0.1 Mn 0.1 O 2 , borate functionalization, disiloxane, electrolyte additive, cycle life

Recent Progress and Prospects on Sodium-Ion Battery and All-Solid-State Sodium Battery: A Promising Choice of Future Batteries for Energy Storage

“…When SIBs are modified to have an anode-free structure and are paired with 20% excess Na metal, the total thickness of the anode is reduced by 20 mm, while the anode material accounts for 44.7% of the total thickness in this case . Yujie Chen et al took NaNi 0.4 Fe 0.2 Mn 0.4 O 2 and LiNi 0.8 Co 0.1 Mn 0.1 O 2 as the cathode materials of AFSBs, SIBs and LIBs and provided an economic analysis and performance introduction of AFSBs. For AFSBs, during the charging process, Na metal is deposited on the anode, which can exhibit a specific capacity of up to 1165 mAh g –1 and a low potential of only 0 V vs Na + /Na.…”