Hierarchical Sulfide‐Rich Modification Layer on SiO/C Anode for Low‐Temperature Li‐Ion Batteries

Abstract

The silicon oxide/graphite (SiO/C) composite anode represents one of the promising candidates for next generation Li-ion batteries over 400 Wh kg −1 . However, the rapid capacity decay and potential safety risks at low temperature restrict their widely practical applications. Herein, the fabrication of sulfide-rich solid electrolyte interface (SEI) layer on surface of SiO/C anode to boost the reversible Li-storage performance at low temperature is reported. Different from the traditional SEI layer, the present modification layer is composed of inorganic-organic hybrid components with three continuous layers as disclosed by time-of-flight secondary ion mass spectrometry (TOF-SIMS). The result shows that ROSO 2 Li, ROCO 2 Li, and LiF uniformly distribute over different layers. When coupled with LiNi 0.8 Co 0.1 Mn 0.1 O 2 cathode, the capacity retention achieves 73% at −20 °C. The first principle calculations demonstrate that the gradient adsorption of sulfide-rich surface layer and traditional intermediate layer can promote the desolvation of Li + at low temperature. Meanwhile, the inner LiF-rich layer with rapid ionic diffusion capability can inhibit dendrite growth. These results offer new perspective of developing advanced SiO/C anode and low-temperature Li-ion batteries.

Insights into the Effect of SiO Particle Size on the Electrochemical Performance between Half and Full Cells for Li-Ion Batteries

“…The SEI film of SiO@C-1 (Figures 5a and S11) is extremely thick and heterogeneous with an average thickness of ∼85 nm, demonstrating that the electrolyte is continuously decomposed at the electrode interface. 47 By contrast, the average SEI film thicknesses of the SiO@C-2 and SiO@C-3 electrodes are only ∼16 and ∼9 nm (Figures 5c,e and S12), respectively, which are much thinner than that of SiO@C-1. Moreover, the carbon layer of the SiO@C-2 and SiO@C-3 electrodes can be observed in the HRTEM images (Figure S12), indicating the thin SEI film and relatively intact structure.…”

“…Figure shows the morphology of the SEI film of the single SiO particle for the three electrodes after 200 cycles. The SEI film of SiO@C-1 (Figures a and S11) is extremely thick and heterogeneous with an average thickness of ∼85 nm, demonstrating that the electrolyte is continuously decomposed at the electrode interface . By contrast, the average SEI film thicknesses of the SiO@C-2 and SiO@C-3 electrodes are only ∼16 and ∼9 nm (Figures c,e and S12), respectively, which are much thinner than that of SiO@C-1.…”

Low-temperature lithium-ion batteries: challenges and progress of surface/interface modifications for advanced performance

“…Although the slow desolvation process greatly hinders the transfer process of Li ions at the interface, a few reports on accelerating the desolvation process of lithium ions by forming artificial SEIs with electrolyte additives exist at present. Liu et al 86 constructed sulfide-containing SEI layers on silicon-based anodes to accelerate Li + desolvation (Fig. 5f).…”

Electronic Modulation and Structural Engineering of Carbon-Based Anodes for Low-Temperature Lithium-Ion Batteries: A Review

“…Secondly, suitable SEI film can also significantly improve battery performance at low temperatures. X. Liu et al presented a novel strategy to create a more stable interface between the electrolyte and electrode by constructing a sulfuric acid-containing SEI layer on top of a silicon-based anode to achieve a SiO/C anode with high performance at low temperatures [35]. The SiO/C composite anode was modified with an electrolyte containing organic-inorganic hybrid components during initial discharge.…”