Hierarchical NiSe₂ Nanosheet Arrays as a Robust Cathode toward Superdurable and Ultrafast Ni–Zn Aqueous Batteries

Abstract

Zn-based aqueous batteries are enjoying the hotspots of worldwide research as their significant merits in economic cost and safety. However, the lack of a robust cathode (positive electrode) owning excellent rate ability, high capacity, and stability challenges their practical application. Herein, we propose hierarchical NiSe 2 nanosheet arrays as a robust cathode toward high-performance Ni−Zn aqueous batteries. Attributed to in situ anion exchange and Kirkendall effects, the nanosheet arrays are hierarchically constructed by NiSe 2 nanoparticles and abundant mesopores, which fully expose the active sites and accelerate the electrode kinetics. This unique structure endows the NiSe 2 electrode with remarkable specific capacity (245.1 mAh g −1 ) and extraordinary high-rate ability (maintains 58% at 72.8 A g −1 ) together with 10,000 cycles without any obvious capacity degeneration. As a result, based on the total active weight, our NiSe 2 //Zn battery is capable of record-high power density (91.22 kW kg −1 /639.1 mW cm −2 ), imposing energy density (328.8 Wh kg −1 /2.303 mWh cm −2 ), and ultralong lifespan (only 8.3% capacity loss after 10,000 cycles), surpassing most of the aqueous batteries and supercapacitors recently reported. Moreover, this NiSe 2 //Zn battery is also affordable (US$40 per kWh) and safe. These results open a new avenue for developing superdurable and ultrafast high-energy Ni−Zn batteries toward affordable and practical energy storage.

Oxygen-Defect Enhanced Anion Adsorption Energy Toward Super-Rate and Durable Cathode for Ni–Zn Batteries

“…) is linear (Fig. 3c) [14]. Figure S10a-c shows the calculated contribution ratio of the three electrodes at various scan rates.…”

“…To date, various alkaline Zn-based cathodes have been developed, such as MnO 2 [9], Ag-based [10], and Ni, Cobased materials (e.g., Ni(OH) 2 [11,12], NiO [13], NiSe 2 [14], Ni 3 S 2 [15,16], Co 3 O 4 [17][18][19], Co 3 S 4 [20], NiCo-DH [21,22], and NiCo 2 O 4 [23][24][25]). While MnO 2 -Zn battery has a low working voltage and weak stability, AgO-Zn battery has low stability, poor overcharge tolerance and high cost.…”

Modulating residual ammonium in MnO2 for high-rate aqueous zinc-ion batteries

“…Recently, a series of significant research efforts have been devoted to designing various cathode materials for aqueous ZIBs, including vanadium oxides, [14][15][16][17][18] MnO 2 , [19][20][21][22] Prussian blue analogues, [23][24][25] organic polymers [26][27][28] and other materials. [29][30][31][32][33] Manganese dioxide (MnO 2 ), as a promising cathode material in aqueous zinc batteries, possesses a moderate voltage plateau, high theoretical capacity, and low cost. 34 However, the undesirable dissolution of Mn 2+ in the aqueous electrolyte derived from Mn 3+ disproportionation (defined as the Jahn-Teller effect) leads to serious capacity decay and structural collapse, especially in long-term cycles.…”

Hierarchical Heterostructure Engineering of Layered Double Hydroxides on Nickel Sulfides Heteronanowire Arrays as Efficient Cathode for Alkaline Aqueous Zinc Batteries

“…All the GCD curves deliver a clear voltage platform, corresponding to the redox peak in the CV curve, which further demonstrates that the electrode undergoes a typical battery behavior. As illustrated in Figure 4e, the excellent specific capacitance of NF\Ni 3 S 2 /NiS@NiCo‐LDH can be calculated to be 434.5 mAh g −1 at the current density of 3 mA cm −2 , which is far more than the recently reported Ni‐based cathodes, such as Ni‐NiO/CC (184 mAh g −1 at 0.625 A g −1 ), [ 19 ] CNF@NiCo 2 S 4 (218 mAh g −1 at 1.26 A g −1 ), [ 20 ] NiCo‐MOF (225 mAh g −1 at 1 A g −1 ), [ 21 ] Ni 2 P (242 mAh g −1 at 1 A g −1 ), [ 22 ] NiSe 2 (243.7 mAh g −1 at 1.4 A g −1 ), [ 23 ] NiCo‐90 (303.6 mAh g −1 at 2 mA cm −2 ), [ 24 ] Mo‐NiS 2 @NiCo‐LDH (325.6 mAh g −1 at 1 A g −1 ), [ 11 ] Ni 4 Co 1 ‐OH (363.6 mAh g −1 at 5 mA cm −2 ), [ 25 ] Ni‐Mo‐Co‐S NCAs/NF (388.1 mAh g −1 at 5 mA cm −2 ), [ 26 ] and Co x Ni 3‐x S 2 @NiCo‐OH (390 mAh g −1 at 5 mA cm −2 ). [ 5b ] In addition, the CV and GCD curves of NF\Ni 3 S 2 /NiS and NF\NiCo‐LDH are also displayed in Figure S7, Supporting Information.…”