Multiscale Observations of Inhomogeneous Bilayer SEI Film on a Conversion‐Alloying SnO₂ Anode

Abstract

The ORCID identification number(s) for the author(s) of this article can be found under https://doi.org/10.1002/smtd.202101111. Figure 7. Solid electrolyte interphase (SEI) formation process and structural evolution of SnO 2 (a), SnO 2 -LiF and SnO 2 -Li 2 CO 3 electrodes (b).

Advancing Performance and Unfolding Mechanism of Lithium and Sodium Storage in SnO2 via Precision Synthesis of Monodisperse PEG‐Ligated Nanoparticles

“…Meanwhile, the extension of charge plateau at 1.08 and 0.17 V in the voltage range of 0.5-1.6 and 0.01-0.5 V, respectivley, suggested the gradual activation of conversion reaction between SnO and Sn (Equation 5) and alloying-dealloying reaction of Sn (Equation 6). [36,37] After the activation process at 20 mA g -1 for ten cycles as anode of SIBs, two pairs of stable discharge/ charge plateaus at 0.67/0.89 V (primary) and 0.21/0.19 V (secondary) were observed in the tenth charge-discharge profiles of SnO 2 @PEG-GO nanohybrids (Figure 4d). Taken together, the extraordinary capacity rising process and regular voltage plateau evolution in the initial cycles of SnO 2 @PEG-GO nanohybrids as anode of SIBs at 50 mA g −1 can be attributed to the gradual activation of the conversion reaction between SnO and Sn and the alloying-dealloying reaction of Sn.…”

Breaking Solvation Dominance of EC via Electron Engineering Enables Battery Operation Below -100℃

“…The depth profiles of TOF-SIMS showed that organic moieties (CH2 -, CO3 -, C2H3O -, and C2H3O2 -) were mainly concentrated on the outface of SEI (Fig 5c-d 42,43,44 . Table S9 listed the attribution of the fragment ions and their potential sources, including three organic components: ROCO2Li (representing CO3fragment), CH3COLi (C2H3O -) and CH3COOLi (C2H3O2 -), which were produced through the electrochemical reduction of EC, DEC and carboxylate, respectively.…”

Insight into Reversible Conversion Reactions in SnO2‐Based Anodes for Lithium Storage: A Review

“…Highly crystalline SnO 2 tends to have poor electrical conductivity for Li + /e − , which is one of the major reasons for the poor Li storage performance of pure SnO 2 . [ 43 ] Therefore, modifying the crystal structure with doping elements has become a major method to accelerate Li + transport, via introducing defects or amorphous active sites. Due to the limitation of the energy barrier for Li + migration, Li + is typically transported only along specific channels, resulting in anisotropy of Li + migration.…”

“…The pure SnO 2 electrode displays fluctuate and declining CEs. [43,56] Moreover, a small reduction in CEs can make the capacity retention decay unacceptably rapidly. Nevertheless, the huge impact of round-trip efficiency seems not widely concerned in reported literatures.…”

“…[41,42] As shown in Figure 1b, the large capacity loss in the first cycle increases the overall cost of LIBs due to the unnecessary consumption of the expensive Li source in the cathode side. [43,44] Moreover, inferior ICE is detrimental to the energy density of Li-ion full cell. Since the supply of Li + in full cell comes from the cathode and is extremely limited, any Li + loss will greatly decrease the energy density of the full cell.…”