A Systematic Study of Electrolyte Additives in Single Crystal and Bimodal LiNi_0.8Mn_0.1 Co_0.1O₂/Graphite Pouch Cells

Abstract

A few weight percent of electrolyte additives can dramatically improve Li-ion battery performance and lifetime. A systematic investigation of a series of electrolyte additive formulations was performed on bimodal (BM) and single crystal (SC) LiNi0.8Mn0.1Co0.1O2 (NMC811)/artificial graphite (AG) pouch cells. Long-term cycling tests at different temperatures (20 °C, 40 °C, and 55 °C) and different upper cutoff voltages (4.06 V and 4.20 V) were performed. These tests results were combined with advanced characterization techniques like ultra-high precision charging (UHPC), ex-situ gas measurement, and automatic cell storage tests to rank the additives based on their effectiveness. Radar plots and a figure-of-merit (FOM) approach were further utilized to summarize results for the BM and SC NMC811/AG cells. This work provides a useful benchmark for those developing NMC811/graphite cells and gives important insights for future electrolyte additive studies.

Radiolysis of Electrolytes in Batteries: A Quick and Efficient Screening Process for the Selection of Electrolyte‐Additive Formulations

“…For instance, a similar study to that presented here could be worth doing based on the recent publication on a battery using a positive electrode (NMC811), which is prone to intense reaction. [ 31 ] They are known to lead to CO 2 production. [ 64 ] Therefore, depending on the experimental conditions, the choice of the marker of the degradation in the radiation chemistry experiments, may be different.…”

“…[ 28 ] Over the years, the same group has continuously been adding more data on other systems till recently and based on similar protocols to that developed in 2014. [ 31 ] In the work performed in 2014, [ 28 ] the relationship between the nature and amount of several additives and the electrochemical performance of the formulation was determined by high precision coulometry and impedance spectroscopy in LiCoO 2 /graphite pouch cells. The authors ranked additives and identified the best ones based on a marker representing the degradation of the battery, i.e., the charge slippage.…”

Data Specifications for Battery Manufacturing Digitalization: Current Status, Challenges, and Opportunities

“…[168] Archimedes' principle has been used to devise a method of monitoring cell volume during operation and provides a more accurate representation of the amount of gas evolution. [169,170] Although these methods give information about the extent of gassing, they do not give information about the composition of the gases. Gas chromatography and mass spectrometry are techniques being developed to identify these gases.…”

“…However, this inaccurately assumes that the expansion is uniform throughout the cell [168] . Archimedes′ principle has been used to devise a method of monitoring cell volume during operation and provides a more accurate representation of the amount of gas evolution [169,170] . Although these methods give information about the extent of gassing, they do not give information about the composition of the gases.…”

Mechanical Pulverization of Co-Free Nickel-Rich Cathodes for Improved High-Voltage Cycling of Lithium-Ion Batteries

“…To mitigate the above issues, several strategies have been attempted: doping, − surface modification, surface modification via intentional electrolyte additive decomposition, − process refinement, , TM concentration gradient, core–shell structures, grain boundary tailoring, and single-crystalline morphology. , Individually, these modifications fail to generate nickel-rich cathode materials with optimum cycle life retention and air stability for commercial use. Particle cracking may still occur with high-voltage cycling, slowly degrading performance, and air instability allows residual lithium compounds to form during material synthesis and electrode production.…”