Constructing Robust Electrode/Electrolyte Interphases to Enable Wide Temperature Applications of Lithium-Ion Batteries

Abstract

The electrolyte generally dictates the working temperature range of lithium-ion batteries (LIBs), thus developing a new class of electrolytes (primarily functional additives) in LIBs for wide temperature applications will be quite essential for further development of LIBs for the electric vehicle market. In this study, we develop new functional electrolytes containing multiple additives to enable the LIBs to perform well in a wide temperature range from −40 to 60 °C. Importantly, those cells based on the above optimized electrolytes have been proven to behave significantly enhanced discharging performance at −40 °C, the long-term cycling stability at 25 °C (more than 85% of capacity retention after 1000 cycles at 1C/1C rates in 1 Ah pouch cells), as well as the obviously improved cycling stability at 60 °C. These remarkable cell performances originate from the highly conductive, uniform, and compact passivating films formed on both anode and cathode surfaces by the synergistic effects of the multiple additives. Our finding on the synergistic benefits originating from a certain additive combination in the optimized electrolytes would favorably widen the working temperature range of future highperformance LIBs.

Ordered LiNi0.5Mn1.5O4 Cathode in Bis(fluorosulfonyl)imide-Based Ionic Liquid Electrolyte: Importance of the Cathode–Electrolyte Interphase

“…[49,56,57] The P2p spectrum supports the observation of P-F species, with peaks observed at 136.20 eV and 134.58 eV for P2p 2/3 , corresponding to Li x PF y and Li x PO y F z , respectively ( Figure S2b,d,and f, Supporting Information). [58,59] The Li x PO y F z is a degraded product from LiPF 6 after 1st charge process based on the following reactions: [60,61] (1) PF 5 +H 2 O → POF 3 + 2 HF (2) POF 3 + ne -+ nLi + → Li x PO y F z + LiF However, it is difficult to observe the LiF formation on H-LNMO after the 1st charge of H-LNMO cells with LP30 electrolyte. It is speculated that the hydrofluoric acid (HF), the resultant byproduct in the reaction between the electrolyte and trace water, attacks the CEI layer.…”

Low‐Temperature Electrolyte Design for Lithium‐Ion Batteries: Prospect and Challenges

“…[77] Alternatively, the phosphoruscontaining compound, such as tris(trimethylsily) phosphite (TTMSPi), N-(trimethylsilyl)diethylamine (TMSDEA), together with the FEC and 1,3-propane sultone (1,3-PS), was used as the additives in the electrolyte of 1.0 M LiPF 6 , 0.05 M CsPF 6 in EC/PC/EMC. [78] A significantly enhanced discharging performance of 66 % was obtained at À 40 °C in the graphite j NCA fullcell at C/5 (Figure 6d). This is because the highly conductive, uniform, and compact passivating films formed on both anode and cathode surfaces, such as the PÀ OÀ Si, F-enriched, or Sbased, and Cs-containing species, as well as the less Li x PF y , LiF, and more Li x PO y F z , which can improve the surface stability and ionic conductivity effectively.…”

“…This is because the highly conductive, uniform, and compact passivating films formed on both anode and cathode surfaces, such as the PÀ OÀ Si, F-enriched, or Sbased, and Cs-containing species, as well as the less Li x PF y , LiF, and more Li x PO y F z , which can improve the surface stability and ionic conductivity effectively. [78] The other kinds of additives, such as the chemical compound with the sulfur element, were also widely used. [79] Firstly, the discharge capacity and rate performance of the Li j LiFePO 4 half-cell at the low temperature (e. g., À 20 °C) are can be enhanced from 40 % to 47.9 % at 0.2 C by adding butyl sultone (BS) (Figure 6d).…”

Toward Critical Electrode/Electrolyte Interfaces in Rechargeable Batteries

“…[ 107 ] However, the severe gassing phenomenon originating from FEC reduction was also observed, especially in pouch cell level. [ 108 ] Except for FEC, other reactive solvents such as vinylene carbonate (VC), [ 70a ] 1,3‐dioxolane (DOL), [ 109 ] trifluoropropylene carbonate (TFPC), [ 110 ] aromatic toluene, [ 111 ] and hydrofluoroether (HFE) [ 112 ] were also extensively investigated to effectively passivate the Li electrodes.…”