An Ultrafast and Stable Li‐Metal Battery Cycled at −40 °C

Abstract

Li-metal battery (LMB) suffers from the unexpected Li dendrite growth and unstable solid-electrolyte interphase (SEI), especially in the extreme conditions, such as high rates and low temperatures (LT). Herein, a high-rate and stable LT LMB is realized by regulating electrolyte chemistry. A weak Li + -solvating solvent 2-methyltetrahydrofuran is used as electrolyte solvent to mitigate the kinetic barrier for Li + de-solvation. Moreover, a co-solvent tetrahydrofuran with a high donor number is incorporated to improve the LT solubility of Li salts, achieving an improved ionic conductivity while maintaining the weak Li + -solvation effect. Furthermore, abundant FSI − anions in contact-ion pairs are presented, facilitating the formation of a stable LiFenriched SEI. Consequently, the Li||Li battery can be operated at 10 mA cm −2 with a small polarization of 154 mV at −40 °C. Meanwhile, an outstanding cumulative cycling capacity of 4000 mAh cm −2 at 8.0 mA cm −2 is achieved, reaching a record high level in LT alkali metal symmetric batteries. Also, rechargeable high-rate and stable full batteries are achieved at −40 °C. This work demonstrates the superiority of electrolyte chemistry for synergistic regulation of both ion transfer kinetics and SEI toward ultrafast and stable rechargeable LMBs at LT.

Regulating the weak solvation structure in electrolyte for high-rate Li-metal batteries at low temperature

“…As the current density is increasing from 0.5C to 2C, a homogeneous deposition can still be kept on the Li anode without dendrite formation in Base-IZ at −40 °C (Fig. 5g-i), demonstrating a fast ion transport kinetics in Base-IZ at LT. 37 However, in Base electrolyte, obvious dendrite and non-uniform lithium deposition could be found even at a current density of 0.5C (Fig. 5f).…”

Cu(II)-Based Metal–Organic Framework Loaded with Silver Nanoparticles as a Catalyst for the A3-Coupling Reaction

“…The characteristic spectra of O 1s could be deconvoluted into three peaks at 531.85, 532.62, and 533.53 eV corresponding to the C–O, CO, and Cu–O bonds (Figure c). The peaks of N 1s located at 399.52, 399.88, 400.3, and 401.91 eV were separately assigned to the N–C, N–S, NC, and N–Cu bonds (Figure d). − Compared with the peaks of N 1s of Cu-MOF 1 (Figure h), a shift of 0.33 eV for the Cu–N bond and a large increase in the proportion of Cu–N bonds could be observed for 0.5Ag/1 , which indicated the strong interactions between N and Ag NPs. , Meanwhile, the XPS spectra of S 2p in 0.5Ag/1 could be separated into four peaks at 165.97, 167.12, 169.03, and 170.24 eV (Figure e), while the S 2p peaks in 1 without Ag NPs were only separated into two peaks at 166.03 and 167.29 eV (Figure i), which also suggested the strong interactions between S and Ag NPs. The XPS spectra of Cu 2p of 0.5Ag/1 exhibited binding energy peaks at 935.34, 940.71, and 944.45 eV, which could be attributed to the split of Cu 2p 3/2 , shakeup satellite of Cu 2p 3/2 line (Figure f).…”

“…To obtain the optimum reaction conditions, the coupling reaction of phenylacetylene, benzaldehyde, and tetrahydropyrrole was chosen as the model reaction. According to previous studies, ,− A 3 -coupling reaction usually afforded considerable yield in acetonitrile, tetrahydrofuran (THF), toluene, and DMF, and thus, we first screened the effect of these solvents on the reaction of phenylacetylene, benzaldehyde, and tetrahydropyrrole. As shown in Table , it could be found that only the reactions in DMF and toluene afforded the desired products and the yield could reach 72 and 95% at 100 °C for 12 h, respectively (Table , entries 5 and 8), while all the reactions in other conditions hardly produced any product.…”

Unlocking Reversible Silicon Redox for High‐Performing Chlorine Batteries

“…In addition, the Cl‐rich electrolyte solvation could benefit the cathode redox between LiCl and Cl 2 , thus ensuring high electrochemical performances even at low temperatures [4] . These results were highly competitive compared with state‐of‐the‐art Li‐ion and Li/Na/K metal batteries working at low temperatures, which exhibited much lower energy efficiency retentions of 16–78 % [17–26] (Figure 3h and Table S3).…”