Ultrafast, Highly Reversible, and Cycle‐Stable Lithium Storage Boosted by Pseudocapacitance in Sn‐Based Alloying Anodes

Abstract

Boosting power density is one of the primary challenges that current lithium ion batteries face. Alloying anodes that possess suitable potential windows stand at the forefront in pursuing ultrafast and highly reversible lithium storage to achieve high power/energy lithium ion batteries. Herein, ultrafast lithium storage in Sn-based nanocomposite anodes is demonstrated, which is boosted by pseudocapacitance benefitting from a high fraction of highly interconnected interfaces of Fe/Sn/Li O. By tailoring the voltage window in the range of 0.005-1.2 V for the alloying/dealloying reactions, such Sn-based nanocomposite anodes achieve simultaneous ultrahigh rate capability, superlong cycling performance, and close-to-100% Coulombic efficiency. The nanocomposite anode delivers a high reversible capacity (≈420 mAh g ) at 1 A g for more than 1200 cycles, corresponding to only 0.016% per cycle of capacity decay. A reversible capacity of 350 mAh g can be maintained at an ultrahigh current density of 80 A g , with 67.3% capacity retention relative to the capacity at 1 A g . This combination of pseudocapacitive lithium storage and spatially confined electrochemical reactions in Sn-based nanocomposite anode materials may pave the way for the development of high power/energy and long life lithium ion batteries.

Few‐Layered Tin Sulfide Nanosheets Supported on Reduced Graphene Oxide as a High‐Performance Anode for Potassium‐Ion Batteries

“…In Figure S11 in the Supporting Information, a positive shift of the anodic peaks with the increase of scan rates is observed. The power‐law relationship between the measured peak current ( I p ) and the sweep rate (ν) can be calculated as follow:where both a and b are adjustable parameters. b reflects the control process of the electrochemical behavior, which can be determined from the slope of the plots of log( I ) versus log(ν) in Figure b.…”

3D Graphene Networks Encapsulated with Ultrathin SnS Nanosheets@Hollow Mesoporous Carbon Spheres Nanocomposite with Pseudocapacitance‐Enhanced Lithium and Sodium Storage Kinetics

“…Obviously, the largest b ‐values of peak 1 and peak 2 for SnS@C‐rGO indicate that the incorporation of 3D rGO networks and HMCSs are effective for the conversion of electrochemical process from diffusion behavior to capacitive process, resulting in a fast Li + intercalation/extraction and excellent cyclic stability. The Li‐ion capacitive contribution ratio can be quantified by splitting the current response ( i ) at a fixed potential ( V ) for diffusion‐controlled reaction ( k 2 v 1/2 ) and capacitive effect ( k 1 v ), as presented in Equation …”

Intercalation Pseudocapacitance Boosting Ultrafast Sodium Storage in Prussian Blue Analogs

“…Considering the three-dimensional open framework andt he weak interaction of Na + with the anion p p electrons, intercalation pseudocapacitance is predicted to play ac rucial rule in realizingu ltrahighr ate performance of LV-CuHCF.C yclic voltammetry (CV) was carried out with variation of the sweep rates (0.1-300 mV s À1 )t o examinet he intercalation behavior of Na + in the LV-CuHCF electrode (Figure 3a and Figure S5). (1)]: [11,20] i ¼ av b Upon increasing the sweep rate, there are peak shifts forb oth cathodic and anodic peaks, as well as the evanescenceo ft he low-voltage peak couple (2.75/3.10 V).…”

“…In principle, the current response i of CV scans can be described as ap owerlaw formula with the sweep rate v [Eq. (1)]: [11,20] i ¼ av b…”