Tailoring electrolyte enables high-voltage Ni-rich NCM cathode against aggressive cathode chemistries for Li-ion batteries.

The LiNi0.8Co0.1Mn0.1O2 (Ni-rich NCM) cathode materials suffer from electrochemical performance degradation upon cycling due to detrimental cathode interface reactions and irreversible surface phase transition when operating at a high voltage (≥4.5 V). Herein, a traditional carbonate electrolyte with lithium difluoro(oxalato)borate (LiDFOB) and tris(trimethylsilyl)phosphate (TMSP) as dual additives that can preferentially oxidize and decompose to form a stable F, B and Si-rich cathode-electrolyte interphase (CEI) that effectively inhibits continual electrolyte decomposition, transition metal dissolves, surface phase transition and gas generation. In addition, TMSP also removes trace H2O/HF in the electrolyte to increase the electrolyte stability. Owing to the synergistic effect of LiDFOB and TMSP, the Li/LiNi0.8Co0.1Mn0.1O2 half cells exhibit the capacity retention 76.3% after 500 cycles at a super high voltage of 4.7 V, the graphite/LiNi0.8Co0.1Mn0.1O2 full cells exhibit high capacity retention of 82.8% after 500 cycles at 4.5 V, and Li/LiNi0.8Co0.1Mn0.1O2 pouch cells exhibit high capacity retention 94% after 200 cycles at 4.5 V. This work is expected to provide an effective electrolyte optimizing strategy compatible with high energy density lithium-ion battery manufacturing systems.

Cheng F ，Zhang X ，Wei P ，Sun S ，Xu Y ，Li Q ，Fang C ，Han J ，Huang Y ... -  《-》

Constructing a Low-Impedance Interface on a High-Voltage LiNi(0.8)Co(0.1)Mn(0.1)O(2) Cathode with 2,4,6-Triphenyl Boroxine as a Film-Forming Electrolyte Additive for Li-Ion Batteries.

Li G ，Liao Y ，Li Z ，Xu N ，Lu Y ，Lan G ，Sun G ，Li W ... -  《-》

Borate-Functionalized Disiloxane as Effective Electrolyte Additive for 4.5 V LiNi(0.8)Co(0.1)Mn(0.1)O(2)/Graphite Batteries.

Chen C ，Guo J ，Wu C ，Duan X ，Zhang L ... -  《-》

Phosphate and Borate-Based Composite Interface of Single-Crystal LiNi(0.8)Co(0.1)Mn(0.1)O(2) Enables Excellent Electrochemical Stability at High Operation Voltage.

Long F ，Liu Y ，Zhu G ，Wang Y ，Zheng H ... -  《Materials》

LiF/Li(3)N-Rich Electrode-Electrolyte Interfaces Enabled by Multi-Functional Electrolyte Additive to Achieve High-Performance Li/LiNi(0.8)Co(0.1)Mn(0.1)O(2) Batteries.

LiPF6-based carbonate electrolytes have been extensively employed in commercial Li-ion batteries, but they face numerous interfacial stability challenges while applicating in high-energy-density lithium-metal batteries (LMBs). Herein, this work proposes N-succinimidyl trifluoroacetate (NST) as a multifunctional electrolyte additive to address these challenges. NST additive could optimize Li+ solvation structure and eliminate HF/H2O in the electrolyte, and preferentially be decomposed on the Ni-rich cathode (LiNi0.8Co0.1Mn0.1O2, NCM811) to generate LiF/Li3N-rich cathode-electrolyte interphase (CEI) with high conductivity. The synergistic effect reduces the electrolyte decomposition and inhibits the transition metal (TM) dissolution. Meanwhile, NST promotes the creation of solid electrolyte interphase (SEI) rich in inorganics on the Li metal anode (LMA), which restrains the growth of Li dendrites, minimizes parasitic reactions, and fosters rapid Li+ transport. As a result, compared with the reference, the Li/LiNi0.8Co0.1Mn0.1O2 cell with 1.0 wt.% NST exhibits higher capacity retention after 200 cycles at 1C (86.4% vs. 64.8%) and better rate performance, even at 9C. In the presence of NST, the Li/Li symmetrical cell shows a super-stable cyclic performance beyond 500 h at 0.5 mA cm-2/0.5 mAh cm-2. These unique features of NST are a promising solution for addressing the interfacial deterioration issue of high-capacity Ni-rich cathodes paired with LMA.

Lei Y ，Xu X ，Yin J ，Xi K ，Wei L ，Zheng J ，Wang Y ，Wu H ，Jiang S ，Gao Y ... -  《-》