Microbial pyrazine diamine is a novel electrolyte additive that shields high-voltage LiNi1/3Co1/3Mn1/3O2 cathodes

Abstract

The uncontrolled oxidative decomposition of electrolyte while operating at high potential (> 4.2 V vs Li/Li+) severely affects the performance of high-energy density transition metal oxide-based materials as cathodes in Li-ion batteries. To restrict this degradative response of electrolyte species, the need for functional molecules as electrolyte additives that can restrict the electrolytic decomposition is imminent. In this regard, bio-derived molecules are cost-effective, environment friendly, and non-toxic alternatives to their synthetic counter parts. Here, we report the application of microbially synthesized 2,5-dimethyl-3,6-bis(4-aminobenzyl)pyrazine (DMBAP) as an electrolyte additive that stabilizes high-voltage (4.5 V vs Li/Li+) LiNi1/3Mn1/3Co1/3O2 cathodes. The high-lying highest occupied molecular orbital of bio-additive (DMBAP) inspires its sacrificial in situ oxidative decomposition to form an organic passivation layer on the cathode surface. This restricts the excessive electrolyte decomposition to form a tailored cathode electrolyte interface to administer cyclic stability and enhance the capacity retention of the cathode.

Robust Electrochemical Performance of LIBs Using a Polymethylene-Based High-Density Carboxylic Acid Binder in Graphite Anodes

“…Water-soluble PFA polymer offers the potential to form thin and stable SEI by preventing electrode cracking during cycling and providing better adhesion to electrode components due to the high concentration of functional groups. As a result, they would enhance the overall electrochemical performance of LIBs. − …”