Coupling quinone cathode with ionic liquid electrolyte is demonstrated to build high-energy and long-life sodium-ion batteries. Computational and spectroscopic studies reveal that the inhibitory effect of ionic liquid on dissolution of quinone correlates with the strong polarity, weak electron donor ability, and low interaction energy. The calix[4]quinone and 5,7,12,14-pentacenetetrone cathodes exhibit significantly improved cycling performance in N-methyl-N-propylpyrrolidinium bis(trifluoromethanesulfonyl)amide than in ether electrolyte. These results would enlighten the design and application of ionic liquid and quinones for organic batteries. HIGHLIGHTSA facile strategy is proposed to suppress the dissolution of quinone electrodes Inhibitory effect of ILs correlates to polarity, donor number, and binding energy [PY13][TFSI] markedly inhibits quinone dissolution C4Q and PT cathodes exhibit better capacity retention in ILs than in ether Wang et al., Chem 5, 364-375 February 14, SUMMARYQuinone-based sodium-ion batteries (SIBs) are highly desirable electrochemical devices with high capacity and low cost but suffer from poor cycle life and low practical energy because of quinone dissolution in aprotic electrolyte. Herein, we report a facile strategy of using ionic liquid (IL) to tackle the dissolution of quinone electrodes. The inhibitory effect of ILs on quinone dissolution correlates with their polarity, donor number, and interaction energy, as revealed by combined density functional theory and spectroscopy studies. Particularly, in N-methyl-N-propylpyrrolidinium bis(trifluoromethanesulfonyl)amide ([PY13] [TFSI]) electrolyte with weak donor ability and large polarity, calix[4]quinone cathode exhibits high capacity (>400 mAh g À1 ) and superior capacity retention ($99.7% at 130 mA g À1 for 300 cycles), significantly outperforming that in etherbased electrolyte. Moreover, the remarkable cyclability and considerable rate capability of 5,7,12,14-pentacenetetrone in [PY13][TFSI] render it a promising sodium-storage material. This work would promote the development of highperformance SIBs with quinone electrodes and IL electrolyte.

No abstract

Solid‐state sodium batteries (SSNBs) have attracted extensive interest due to their high safety on the cell level, abundant material resources, and low cost. One of the major challenges in the development of SSNBs is the suppression of sodium dendrites during electrochemical cycling. The solid electrolyte Na3.4Zr2Si2.4P0.6O12 (NZSP) exhibits one of the best dendrite tolerances of all reported solid electrolytes (SEs), while it also shows interesting dendrite growth along the surface of NZSP rather than through the ceramic. Operando investigations and in situ scanning electron microscopy microelectrode experiments are conducted to reveal the Na plating mechanism. By blocking the surface from atmosphere access with a sodium‐salt coating, surface‐dendrite formation is prevented. The dendrite tolerance of Na | NZSP | Na symmetric cells is then increased to a critical current density (CCD) of 14 mA cm−2 and galvanostatic cycling of 1 mA cm−2 and 1 mAh cm−2 (half cycle) is demonstrated for more than 1000 h. Even if the current density is increased to 3 mA cm−2 or 5 mA cm−2, symmetric cells can still be operated for 180 h or 12 h, respectively.