Distinct Reaction Characteristics of Electrolyte Additives for High-Voltage Lithium-Ion Batteries: Tris(trimethylsilyl) Phosphite, Borate, and Phosphate

Prescribing Functional Additives for Treating the Poor Performances of High‐Voltage (5 V‐class) LiNi0.5Mn1.5O4/MCMB Li‐Ion Batteries

“…The addition of TMSP and PCS binary functional additives does work to change the surface morphology of long-term cycled LiNi 0.5 Mn 1.5 O 4 and MCMB electrodes (typical scanning electron microscopy (SEM) images in Figures S4-S7, Supporting Information). [35,[48][49][50][51][52][53] It is well known cycle, with a) BE and b) BE + binary functional additives (1 wt% TMSP + 1 wt% PCS) at 1 C rate, respectively. [35,[48][49][50][51][52][53] It is well known cycle, with a) BE and b) BE + binary functional additives (1 wt% TMSP + 1 wt% PCS) at 1 C rate, respectively.…”

“…[25,35,39,[48][49][50][51][52][53] Some of the dissolved transition metal ions will migrate through separators to deposit on graphite anode surface, catalyzing excessive irreversible electrolyte reduction and consuming the limited active lithium in full cell. [25,35,39,[48][49][50][51][52][53] Some of the dissolved transition metal ions will migrate through separators to deposit on graphite anode surface, catalyzing excessive irreversible electrolyte reduction and consuming the limited active lithium in full cell.…”

“…[8,[31][32][33][34][35][36][37][38][39][40][43][44][45][46][47] To develop new functional additives for electrolyte, molecular orbital (MO) calculation is used as a first screening method. [35,[48][49][50][51][52][53] With a higher HOMO energy relative to carbonate solvents, TMSP easily undergoes electrochemi cal oxidations and promotes the formation of a protective SEI layer on the surface of high-voltage cathode materials (such as LiNi 0.5 Mn 1.5 O 4 , LiNi 0.5 Co 0.2 Mn 0.3 O 2 , overlithiated layered oxide). Specifically speaking, functional additives with a higher HOMO energy than carbonate solvents will be preferentially oxidized to modify the cathode SEI layer, while those with a lower LUMO energy than carbonate solvents will be preferentially reduced to modify the anode SEI layer.…”

Tris(trimethylsilyl) Phosphite (TMSPi) and Triethyl Phosphite (TEPi) as Electrolyte Additives for Lithium Ion Batteries: Mechanistic Insights into Differences during LiNi0.5Mn0.3Co0.2O2-Graphite Full Cell Cycling

“…20 Detailed mechanistic investigations on the use of TMSPi as an electrolyte additive are limited [17][18][19]22 and in all reported systems the observed benefits of TMSPi have been attributed to two common traits: formation of a protective film on the cathode, and elimination of HF from the electrolyte. While the reaction of HF with trimethylsilyl (TMS) groups is well documented both experimentally 18,22 and computationally, 19,23,25 the formation of TMSPi-based surface films is poorly understood. Even less is known about the effects of triethylphosphite (TEPi) (Figure 1) in LIB cells: the compound has been shown to benefit cells by acting as an oxygen scavenger 28 and as a flame retardant.…”

“…[15][16][17][18][19][20][21][22][23][24][25][26][27] Various studies have investigated the use of TMSPi in binary mixtures with compounds, such as vinylene carbonate (VC), 26 and in ternary mixtures of TMSPi and other additives. 20,21 For example, in a comprehensive study performed by Dahn and coworkers (which examined over 110 electrolyte additive blends), a ternary mixture containing 2 wt% prop-1-ene-1,3 soltone (PES) + 1 wt% methylene methane disulfonate (MMDS) + 1 wt% TMSPi was shown to give a combination of high coulombic efficiency, low impedance, and superior long term performance in NMC333/Graphite (Gr) full cells (2.8-4.2 V range), out-performing all the other electrolyte additive blends.…”