Fluorinated carbon nitride with a hierarchical porous structure ameliorating PEO for high-voltage, high-rate solid lithium metal batteries

Abstract

Hierarchical porous fluorinated carbon nitride (FCN) fillers induced the formation of a LiF- and Li3N-rich composite SEI layer and effectively suppressed the lithium dendrite growth in high-voltage, high-rate ASSLBs.

Multipolar Conjugated Polymer Framework Derived Ionic Sieves via Electronic Modulation for Long‐Life All‐Solid‐State Li Batteries

“…The 0.5 %CNF-COF@PEO electrolyte exhibits a much higher t Li + of 0.81 (Figure 3e) relative to the PEO counterpart (0.22) (Figure S11) and even surpassing most reported PEO-based solid electrolytes involving different functional fillers under comparable conditions. [6,20,21,[23][24][25][47][48][49] As indicated in Figure S3 and S12, at 30 °C, the ionic conductivity and t Li + of the 0.5 %CNF-COF@PEO SPE are 2.65×10 À 5 S cm À 1 and 0.37, higher than 0.5 %CNF-COP@PEO SPE (1.90×10 À 5 S cm À 1 and 0.33), indicating the promoting role of crystalline structure, while 0.5 %CNF-COP@PEO SPE outperforms 0.5 %F-COP @PEO SPE (1.16×10 À 5 S cm À 1 , 0.22) and 0.5 %CN-COP@-PEO SPE (1.46×10 À 5 S cm À 1 , 0.27), implying the key role of -CN and F dual-decoration in Li ion conduction, consistent with the theoretical prediction. Similar trends are also observed in term of the ionic conductivity at 60 °C: CNF-COF@PEO > CNF-COP@PEO > CN-COP@PEO > F-COP@PEO > COP@PEO (Figure S4).…”

“…Such cycling performance metric surpasses almost all literature-reported results using various PEO-based SPE under comparable conditions (Figure 6f). [6,20,21,23,25,48,49,53] Notably, at a higher LFP loading of 4.9 mg cm À 2 , the Li/0.5 %CNF-COF@PEO SPE/LiFePO 4 cell yields an initial capacity of 137.2 mAh g À 1 at 0.2 C with impressive capacity retention of 97.2 % over 500 cycles (Figure 6h). At 50 °C, the 0.5wt %CNF-COP@PEO SPE equipped battery can also perform well and deliver the initial discharge capacity of 89 mAh g À 1 at 2 C with a large retention of 98.8 % after 260 cycles (Figure S27).…”

“…[16][17][18][19] Despite some advances, those reported fillers generally demand relatively high loading (typically � 5 wt %) in the polymer electrolyte towards the optimal performance, while higher filler loading tends to engender undesired agglomeration, leading to uneven Li ion transport. [6,20,21] Worse still, serious Li dendrite growth is commonly seen, especially over multiple charge/ discharge cycles and at high current density, and the existing PEO-based polymer electrolytes seldom display stable cycling performance for more than 1000 times at high rate (e.g. 2 C) and even at elevated temperatures (e.g.…”

Multipolar Conjugated Polymer Framework Derived Ionic Sieves via Electronic Modulation for Long‐Life All‐Solid‐State Li Batteries

“…The 0.5 %CNF-COF@PEO electrolyte exhibits a much higher t Li + of 0.81 (Figure 3e) relative to the PEO counterpart (0.22) (Figure S11) and even surpassing most reported PEO-based solid electrolytes involving different functional fillers under comparable conditions. [6,20,21,[23][24][25][47][48][49] As indicated in Figure S3 and S12, at 30 °C, the ionic conductivity and t Li + of the 0.5 %CNF-COF@PEO SPE are 2.65×10 À 5 S cm À 1 and 0.37, higher than 0.5 %CNF-COP@PEO SPE (1.90×10 À 5 S cm À 1 and 0.33), indicating the promoting role of crystalline structure, while 0.5 %CNF-COP@PEO SPE outperforms 0.5 %F-COP @PEO SPE (1.16×10 À 5 S cm À 1 , 0.22) and 0.5 %CN-COP@-PEO SPE (1.46×10 À 5 S cm À 1 , 0.27), implying the key role of -CN and F dual-decoration in Li ion conduction, consistent with the theoretical prediction. Similar trends are also observed in term of the ionic conductivity at 60 °C: CNF-COF@PEO > CNF-COP@PEO > CN-COP@PEO > F-COP@PEO > COP@PEO (Figure S4).…”

“…Such cycling performance metric surpasses almost all literature-reported results using various PEO-based SPE under comparable conditions (Figure 6f). [6,20,21,23,25,48,49,53] Notably, at a higher LFP loading of 4.9 mg cm À 2 , the Li/0.5 %CNF-COF@PEO SPE/LiFePO 4 cell yields an initial capacity of 137.2 mAh g À 1 at 0.2 C with impressive capacity retention of 97.2 % over 500 cycles (Figure 6h). At 50 °C, the 0.5wt %CNF-COP@PEO SPE equipped battery can also perform well and deliver the initial discharge capacity of 89 mAh g À 1 at 2 C with a large retention of 98.8 % after 260 cycles (Figure S27).…”