Hierarchical Micro‐Nanoclusters of Bimetallic Layered Hydroxide Polyhedrons as Advanced Sulfur Reservoir for High‐Performance Lithium–Sulfur Batteries

Abstract

Rational construction of sulfur electrodes is essential in pursuit of practically viable lithium-sulfur (Li-S) batteries. Herein, bimetallic NiCo-layered double hydroxide (NiCo-LDH) with a unique hierarchical micro-nano architecture is developed as an advanced sulfur reservoir for Li-S batteries. Compared with the monometallic Co-layered double hydroxide (Co-LDH) counterpart, the bimetallic configuration realizes much enriched, miniaturized, and vertically aligned LDH nanosheets assembled in hollow polyhedral nanoarchitecture, which geometrically benefits the interface exposure for host-guest interactions. Beyond that, the introduction of secondary metal intensifies the chemical interactions between layered double hydroxide (LDH) and sulfur species, which implements strong sulfur immobilization and catalyzation for rapid and durable sulfur electrochemistry. Furthermore, the favorable NiCo-LDH is architecturally upgraded into closely packed micro-nano clusters with facilitated long-range electron/ion conduction and robust structural integrity. Due to these attributes, the corresponding Li-S cells realize excellent cyclability over 800 cycles with a minimum capacity fading of 0.04% per cycle and good rate capability up to 2 C. Moreover, highly reversible areal capacity of 4.3 mAh cm −2 can be achieved under a raised sulfur loading of 5.5 mg cm −2. This work provides not only an effective architectural design but also a deepened understanding on bimetallic LDH sulfur reservoir for high-performance Li-S batteries.

Designing principles of advanced sulfur cathodes toward practical lithium‐sulfur batteries

“…Various metals and metal-based compounds, such as single atoms, 98 metals, 99 oxides, 100 sulfides, 101 selenides, 102 hydroxides, 103 nitrides, 104 phosphides, 105 carbides, 106 fluorides, 107 tellurides, 82 borides, 108 iodides, 109 bismuth oxychlorides, 110 MOFs, 111 covalent-organic frameworks, 112 and polyoxometalates, 113 exhibit quite different LiPSs affinity. Moreover, modulating the exposed crystal faces can further regulate the adsorption ability.…”

“…Another merit of this technique is improving the whole structural integration for further enhancing the long-range electron/ion transport rate and decreasing internal porosity. 103 To date, the spray-drying method has been widely used in Li-S cathode hosts fabrication. 193,202 3D printing 3D printing is a powerful technique that is capable of fabricating electrodes with high active material loading to improve the energy density of cathodes.…”

NiCo (oxy)selenide electrocatalysts via anionic regulation for high-performance lithium–sulfur batteries

“…S18b and Table S2 †), when taking into consideration the specic capacities, decay rates in long cycles, and sulfur loading. 28,40,[51][52][53][54][55][56][57]…”

Engineering Oversaturated Fe‐N5 Multifunctional Catalytic Sites for Durable Lithium‐Sulfur Batteries

“…Based on the above analysis,t he Fe-N 5 -C with oversaturated Fe-N 5 active site effectively reduces the energy barrier of LiPS conversion and Li 2 Snucleation, and accelerates the electrochemical reaction kinetics. [26] Besides,t he linear sweep voltammetry (LSV) was investigated to explore the Li 2 So xidization behavior on the surfaces of different substrate in Figure 4h. [27] TheF e-N 5 -C shows the lowest onset potential of À0.49 Va nd highest current response among three samples,s uggesting superior conversion kinetics from solid Li 2 St os oluble LiPS.A dditionally,t he electrocatalytic conversion behavior can also be demonstrated by the smallest Tafel slope of Fe-N 5 -C (24 mV dec À1 )c ompared with N-C (108 mV dec À1 )a nd Fe-N 4 -C (31 mV dec À1 )( Figure 4i).…”