Using a lithium bis(oxalato) borate additive to improve electrochemical performance of high-voltage spinel LiNi0.5Mn1.5O4 cathodes at 60°C

Effect of Lithium Bis(oxalato)borate Additive on Electrochemical Performance of Li1.17Ni0.17Mn0.5Co0.17O2Cathodes for Lithium-Ion Batteries

“…This result means that the oxygen in the LiBOB-derived SEI is relatively abundant. 15 The decomposition products formed on the cathode in the reference electrolyte and LiBOB-added electrolyte are identified in the P 2p and F 1s XPS spectra of Fig. 5.…”

Lifetime limit of tris(trimethylsilyl) phosphite as electrolyte additive for high voltage lithium ion batteries

“…In addition, the 19 F-NMR spectrum (Fig. 3a) shows two sets of doublets at À84.04 ppm and À84.06 ppm with 1 J PF coupling constants of 967 (2 and 2 0 ) and 1005 (3 and 3 0 ) Hz respectively which are assigned to OPF(OMe) 2 and OPF(OEt) 2 . However, due to the low signal intensity of the 31 P-NMR spectrum (Fig.…”

The Role of Additives in Improving Performance in High Voltage Lithium-Ion Batteries with Potentiostatic Holds

“…This work investigates some conclusions in the available literature of an additive molecule that decomposes on the charged cathode surface and passivates the surface against electrolyte oxidation. With the goal of increasing battery energy density for transportation applications, layered transition metal oxides cathodes of the form LiMO 2 (M = Ni, Co, Mn) have received significant attention.1-7 While these cathode materials have a high theoretical gravimetric capacity of ∼280 mAh/g, 8 achieving the high capacity of these materials requires very high charging voltages (>4.5V vs. Li + /Li), 2-4 above the stability range of conventional carbonate electrolytes.9,10 Enabling the additional high voltage capacity of the cathode materials requires new electrolytes that provide additional stability at high voltages at the charged cathode surface.The approach to creating compatible electrolytes has mainly fallen along two separate paths: either increasing the intrinsic anodic stability of the electrolyte, [11][12][13][14][15][16][17] or using a sacrificial component in small amounts (an additive) to "passivate" the cathode surface and inhibit continual electrolyte oxidation.18 20,32 have shown evidence of decomposition on various high voltage cathode surfaces through a variety of surface characterization techniques, including attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and X-ray photoelectron spectroscopy (XPS).However, this cathode "passivation" is conventionally inferred through a combination of experimental results, such as increased capacity retention, voltammetric methods indicating a lower anodic stability attributed to additive oxidation, changes to the XPS and/or FTIR spectra of the cathode that include components of the additive, and decreased impedance after cycling. While the results provided by the previously mentioned characterization methods can be reconciled with the conclusion that cathode "passivation" led to the improvement, this mechanistic process can be more accurately evaluated by monitoring the electrolyte oxidation current at a charged cathode surface through potentiostatic holds.…”

“…18 20,32 have shown evidence of decomposition on various high voltage cathode surfaces through a variety of surface characterization techniques, including attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and X-ray photoelectron spectroscopy (XPS).…”

“…[18][19][20][21][22][23] Among additives tested, vinylene carbonate, 21,24,25 phosphites, [26][27][28][29] fluorinated carbonates, 30,31 and borates 20,32 have shown evidence of decomposition on various high voltage cathode surfaces through a variety of surface characterization techniques, including attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and X-ray photoelectron spectroscopy (XPS).…”