Tailoring sodium intercalation in graphite for high energy and power sodium ion batteries

Abstract

Co-intercalation reactions make graphite as promising anodes for sodium ion batteries, however, the high redox potentials significantly lower the energy density. Herein, we investigate the factors that influence the co-intercalation potential of graphite and find that the tuning of the voltage as large as 0.38 V is achievable by adjusting the relative stability of ternary graphite intercalation compounds and the solvent activity in electrolytes. The feasibility of graphite anode in sodium ion batteries is confirmed in conjunction with Na 1.5 VPO 4.8 F 0.7 cathodes by using the optimal electrolyte. The sodium ion battery delivers an improved voltage of 3.1 V, a high power density of 3863 W kg −1 both electrodes , negligible temperature dependency of energy/power densities and an extremely low capacity fading rate of 0.007% per cycle over 1000 cycles, which are among the best thus far reported for sodium ion full cells, making it a competitive choice in large-scale energy storage systems.

A Novel NASICON‐Type Na4MnCr(PO4)3 Demonstrating the Energy Density Record of Phosphate Cathodes for Sodium‐Ion Batteries

“…In recent years, Na superionic conductor (NASICON)-structured Na 3 V 2 (PO 4 ) 3 and its derivatives have been extensively investigated as two-electron reaction SIB cathode materials, [25][26][27][28][29][30][31][32] the Na 3 V 2 (PO 4 ) 3 can deliver a reversible capacity of ≈110 mA h g −1 with a relatively high voltage plateau positioned at 3.4 V, realizing a promising energy density of about 370 Wh kg −1 . [26][27][28][29] Furthermore, the introduction of inductive F − into Na 3 V 2 (PO 4 ) 3 to form Na 3 V 2 (PO 4 ) 2 O x F 3−x (x = 0-2) was identified to be an effective approach to elevate the working potential, [33][34][35] thereby the energy density could be significantly…”

“…We have also summarized the full cell performance in terms of cyclic stability, energy density, and output voltage of the recently reported works (Table S4, Supporting Information), the overall performance especially the high energy density of the present work is outstanding among its peers. [14,33,34] Moreover, the excellent temperature stability of the full cell under the voltage interval of 1.2-4.6 V at 0.2 C is elucidated in Figure 6f, which presents discharge capacities of 106.5 mA h g −1 , 126.0 mA h g −1 , 134.8 mA h g −1 , 142.2 mA h g −1 , and 147.5 mA h g −1 at −10 °C, 0 °C, 25 °C, 40 °C, and 60 °C, respectively. The insert digital photo of Figure 6d demonstrates that the coin-type full cell can continuously light up dozens of light-emitting diodes, showing a great prospect for practical applications.…”

Composites of Sb2O4 and Biomass‐Derived Mesoporous Disordered Carbon as Versatile Anodes for Sodium‐Ion Batteries

“…The challenge is compounded in case of anodes since graphite which is the anode material used in commercial lithium ion batteries, exhibits a meagre reversible capacity of 35 mAh g −1 in case of SIBs when normal sodium salt‐based electrolyte is used . Optimization of the co‐intercalation potential of graphite is possible by using ether‐based electrolytes which leads to graphite anodes with 100–200 mAh g −1 capacity in SIBs . However, the low reaction potential of Na results in its dendritic deposition in graphite during the charging process, which raises serious safety issues .…”

Manipulating Molecular Structure and Morphology to Invoke High‐Performance Sodium Storage of Copper Phosphide

“…[ 7 ] During the past few years, searching for new electrode materials has been on the upsurge and rational modifications were further adopted to optimize the structural stability and enhance the sodium storage property, such as molecular engineering and morphology construction. [ 8–16 ] It is well‐known that copper metal has been widely applied in electronic devices benefiting from low cost and high electronic conductivity. In case of battery field, it can be served as the collector to converge current but not as electrode for energy storage.…”