High‐Energy Rechargeable Metallic Lithium Battery at −70 °C Enabled by a Cosolvent Electrolyte

Abstract

Supportinginformation and the ORCID identification number(s) for the author(s) of this article can be found under: https://doi.

Exploiting Mechanistic Solvation Kinetics for Dual‐Graphite Batteries with High Power Output at Extremely Low Temperature

“…It is worth noting that due to the adoption of the new electrolyte the graphite k LCO control cell ranks among the best capacity retention for this temperature,a sd isplayed by the performance comparison in Figure S5. [6] Despite the high-performing control, the graphite k graphite DIB was found to far exceed the LIB capacity retention, retaining 93.1 %a nd 84.4 %o fi ts room temperature capacity at À40 8 8Ca nd À60 8 8C, respectively ( Figure 3B). Thel ow temperature improvement of the DIB mechanism was further investigated at À60 8 8Cu nder different discharge rates,w hich provided perhaps the most salient deviation of performance metrics (Figure 3C,D).…”

“…To simulate low temperature device operation, the assembled full-cells were then subjected to testing using am ethod similar to previous studies (Supporting Information). [5,6] At À40 8 8Cw ith a1Cd ischarge rate the graphite k LCO LIB was found to retain 72.4 %ofits room temperature capacity,which decreased to 63.2 %atÀ60 8 8C( Figure 3A). It is worth noting that due to the adoption of the new electrolyte the graphite k LCO control cell ranks among the best capacity retention for this temperature,a sd isplayed by the performance comparison in Figure S5.…”

“…[16] However,DIBs could be ideal for applications requiring high power output at extremely low temperature due to the sluggish kinetics of LIBs. [2,6] To better understand the remarkable kinetic performance of the DIB at extremely low temperature,f urther electrochemical characterization was performed on the graphite and LCO positive electrodes to isolate the source of the two storage mechanisms.F irst, the galvanostatic intermittent titration technique (GITT) was applied to the two positive electrodes at room temperature and À60 8 8C ( Figure 4A,B), at echnique which has…”

“…[5] These resistances are all significantly exacerbated at temperatures below À20 8 8Ca nd at high discharge rate,w here Li + de-solvation in particular has been observed to dominate the capacity fade. [5] In general, these resistances have been minimized by employing low meltingpoint solvents, [6] and novel salt additives. [7] Though much progress has been made,i ti sc rucial to note that these advancements have been largely been applied conventional LIBs containing transition-metal oxide electrodes.T hese electrodes operate via the "rocking chair" mechanism, where Li + diffuses from negative electrode to positive electrode during discharge,u ndergoing solvation at the negative electrode interface and de-solvation at the positive electrode interface.A saconsequence of such am echanism, sluggish Li + desolvation is completely unavoidable during both charge and discharge of LIBs.T his is not the case for dual-ion batteries (DIBs), however.D IBs store both cations and anions during charge,w hich migrate back into the electrolyte during discharge.T his "salt-splitting" mechanism intrinsically decouples solvation and desolvation, where ions undergo desolvation on both electrodes during charge and solvation on both electrodes during discharge,t heoretically circumventing the desolvation barrier.…”

Sustainable Battery Materials from Biomass

“…With ionic conductivities in the range of 0.2 mS cm −1 at temperatures as low as −70 °C and almost 1 mS cm −1 at −30 °C, an electrolyte based on LiTFSI dissolved in ethyl acetate could be used under extreme temperatures. At the low end of the investigated temperature range, some inorganic electrode materials could not be employed, so the authors also studied the applicability of lithium metal electrodes and the use of this electrolyte in an all‐organic setup with polymeric electrodes . Therefore, this approach is an important step towards more sustainable batteries.…”