PDF Publication Title:
Text from PDF Page: 007
4.0 3.5 3.0 2.5 2.0 0.1 C 0.1 C 0.2 C PVDF 120 Na alginate 100 5 C 80 10C 60 20C 40 20 0 100 80 60 40 20 0 0 20 40 60 80 100 120 140 160 Gravimetric Capacity (mAh/g) 0 5 10 15 20 25 30 35 40 Cycle No. 0 100 200 300 400 500 Cycle No. is known to be unstable in water and humidity [24]. We find that the water-unstable Na0.67MnO2 has been partially decomposed by exchanging Na+ with H+ and ultimately in- tercalating H2O between the Mn-O layers, as confirmed by XRD in Figure 5. While one can speculate that some of the intercalated hydrogen can later be displaced with Na again, it has been shown that air-exposed electrodes display decreased rate capability, gravimet- 7 of 18 0.1 C Batteries 2022, 8, 6 4.0 PVDF 3.5 3.0 2.5 2.0020406080100120140 Gravimetric Capacity (mAh/g) (a) ric capacity, and worse cyclability. This is indeed what we see in this study (Figure 4), as the gravimetric capacity of Na alginate-based electrodes is significantly reduced. PVDF Na Alginate TBA Alginate 0.1 C 0.2 C 0.5 C 1 C 2 C 5 C 10 C 20 C 160 0.1 C 0.2 C 0.5 C 1C 2C 5C 10C 0.2 C 3.0 0.5 C 1 C 2 C 5 C 2.00 20 40 60 80 100 120 140 160 Gravimetric Capacity (mAh/g) corresponds to 175 mA/g. * * * * § - Buserite 20 Na0.67MnO2 powder 40 2q(°)60 80 100 * ° ° °°° ° ° Electrode: Na alg 4.0 Na Alginate 3.5 3.0 2.5 4.0 TBA Alginate 3.5 2.0020406080100120 Gravimetric Capacity (mAh/g) * - Birnessite ? - Unknown ° - Al foil substrate *§ ?* Powder: 24 h in H2O ***** (b) Charge / discharge capacity 140 (c) CE / Discharge capacity PVDF Na Alginate TBA Alginate 180 160 140 120 100 80 60 40 20 0 (d) Batteries 2022, 8, x FOR PEER REVIEW Figure 4. Electrochemical properties of Na0.67MnO2 electrodes prepared with PVDF, Na7aolgfin19ate TBA alginate binders: charge-discharge curves of Na0.67MnO2 electrodes with (a) PVDF binder, (b) and TBA alginate binders: charge-discharge curves of Na0.67MnO2 electrodes with (a) PVDF binder, Na alginate binder, (c) TBA alginate binder; (d) charge-discharge curves at 0.1 C (17.5 mA/g); (e) (b) Na alginate binder, (c) TBA alginate binder; (d) charge-discharge curves at 0.1 C (17.5 mA/g); (e) rate capability of Na0.67MnO2 electrodes; (f) cycle life of Na0.67MnO2 electrodes cycled at 1 C; 1 C rate capability of Na0.67MnO2 electrodes; (f) cycle life of Na0.67MnO2 electrodes cycled at 1 C; 1 C 0.5 C 1C TBA alginate * * * Powder: 4 h in H2O °°° ° ° Electrode: PVDF 2C (e) Figure 4. Electrochemical properties of Na0.67MnO2 electrodes prepared with PVDF, Na alginate and corresponds to 175 mA/g. FigFuigruere5.5X.RXDRDofoNfaN0.6a7MnMOn2OelecetlreocdtreosdpesrepraerpedarewditwhitPhVPDVFDaFndanNdaNalgailngainteatbeinbdinedrse,rsa,nadnd 0.67 2 Na0.67MnO2 powder—pristine and after 4 h and 24 h of water exposure. Na0.67MnO2 powder—pristine and after 4 h and 24 h of water exposure. ThTehpehmaseeasaussreodciastpeedciwficithdiwscahtaerg-excpaopsaucrietyofoNf TaBxMAOa2lg(Mina–tet-rbaanseitdioNnametMal)niOs beirl-ec- 0.67 2 netsrsoidte, aisnd16i4t hmasAahn/ginacrte1a7s.e6dminAte/rglaycuerrdeinst.anTcheicsoemxpceaerdeds tmooPs2t-toyfpteheNrae0.p67oMrtneOd2c[a4p3]a.ci- Futriethsemreinatseurrceadlawtioitnhionfswimatielrarisvaoslstaogcieawtedinwdoitwh,feovremnadtiopneodfPth2e-tybpueseNriate0.6p7hMasOe2.Dmeastpeirtieals (M—transition metal oxide) [11,17,21,23,45,46]. Our literature survey also suggests that on the hydrated (birnessite) phase being electrochemically active and capable of storing so- average, P2-type Na MO compounds see their discharge capacity decrease by 15% over dium with a gravimet0r.i6c7char2ge of at least 84 mAh/g [44], the value is significantly lower the first 100 cycles. Depending on how this is calculated, we see the discharge capacity than the roughly 160 mAh/g observed for pristine P2-type Na0.67MnO2. As shown in Figure decrease by 8–10%, which is at least a 5% reduction in ageing rate. Of course when com- 5, we found that within 4 h of water exposure (4 h is the time needed to ensure proper pared to state-of-art in LIBs, there is still much room for improvement with regard to cycle mixing of electrode slurry), birnessite impurities have already become apparent. If water life. However, we expect that combining TBA alginate binder with Na MO [22,31] or exposure is continued, after 24 h almost none of the original structure i0s.67retain2ed, and most peaks can be attributed to birnessite or buserite phases. A third phase also appears. Although the lack of additional peaks means that we are not able to pinpoint the impurity phase with a reasonable accuracy, the peak is not associated with Na2CO3 or NaHCO3. The connection to NaOH or its hydrates, however, cannot be ruled out. When using TBA alginate binder, we are able to eliminate the exposure to water while still using a salt of alginic acid as a binder. Results in Figure 4c show that electrodes 2.5 10C 20 C (f) Intensity (a.u.) Voltage (V) Voltage (V) Gravimetric Capacity (mAh/g) Voltage (V) Gravimetric Capacity (mAh/g) Voltage (V) Coulombic Efficiency (%)PDF Image | Na-Ion Batteries Tetrabutylammonium Alginate Binder
PDF Search Title:
Na-Ion Batteries Tetrabutylammonium Alginate BinderOriginal File Name Searched:
batteries-08-00006.pdfDIY PDF Search: Google It | Yahoo | Bing
Salgenx Redox Flow Battery Technology: Salt water flow battery technology with low cost and great energy density that can be used for power storage and thermal storage. Let us de-risk your production using our license. Our aqueous flow battery is less cost than Tesla Megapack and available faster. Redox flow battery. No membrane needed like with Vanadium, or Bromine. Salgenx flow battery
CONTACT TEL: 608-238-6001 Email: greg@salgenx.com (Standard Web Page)