Tailoring Low Temperature Performance of Lithium-ion Battery via Rational Designing Interphase on Anode.

Performance of lithium-ion batteries at sub-ambient temperatures are extremely restricted by the resistive interphases originated from electrolyte decomposition, especially on the anode surface. This work reports a novel strategy that anode interphase of low impedance is constructed by applying an electrolyte additive dimethyl sulfite (DMS). Electrochemical measurements indicate that the as-constructed interphase provides graphite/LiNi0.5Co0.2Mn0.3O2 pouch cells with excellent lower temperature performance, outperforming the interphase constructed by 1,3,2-Dioxathiolane 2,2-dioxide (DTD), a common commercially used electrolyte additive. Spectral characterizations in combination with theoretical calculations demonstrate that the improved performance is attributed to the unique molecular structure of DMS, which presents appropriate reduction activity and constructs the more stable and ionically conductive anode interphase, due to the weaker combination of its reduction product with lithium ions than DTD. This rational design of interphases via additive structure has been proven to be a low cost but rather effective approach to tailor the performances of lithium-ion batteries.