Nanoflakes of Ni–Co LDH and Bi₂O₃ Assembled in 3D Carbon Fiber Network for High-Performance Aqueous Rechargeable Ni/Bi Battery

Abstract

For aqueous nickel/metal batteries, low energy density and poor rate properties are among the limiting factors for their applications, although they are the energy storage systems with high safety, high capacity, and low production cost. Here, we have developed a class of active materials consisting of porous nanoflakes of Ni-Co hydroxides and BiO that are successfully assembled on carbon substrates of carbon cloth/carbon nanofiber 3D network (CC/CNF). The combination of the porous Ni-Co hydroxides/BiO nanoflakes with carbon substrate of 3D network is able to provide a large surface area, excellent conductivity, and promote synergistic effects, as a result of the interaction between the active materials and the carbon matrix. With the porous Ni-Co hydroxides and BiO nanoflakes, the Ni/Bi battery can deliver a high capacity of ∼110 mA h g at a current density of 2 A g. About 80% of its capacity (85 mA h g) can be retained when the current density increases to 20 A g. The full cell can also maintain 93% of the initial capacity after 1000 charge/discharge cycles, showing great potential for Ni/Bi battery.

In Situ Activation of 3D Porous Bi/Carbon Architectures: Toward High‐Energy and Stable Nickel–Bismuth Batteries

“…At a high rate even up to 120 mA cm −2 , the Ni//Bi battery yielded a highly reversible capacity of 0.79 mA h cm −2 and recovered to around 1.36 mA h cm −2 when switched back to 6 mA cm −2 , revealing its fast reaction kinetics and excellent high rate performance. Moreover, the Ni//Bi battery exhibited outstanding long‐term cycling stability with a negligible capacity fading of 6% after 5000 cycles (Figure e), which surpasses most of reported aqueous batteries and asymmetric supercapacitors (ASCs), for instance, a Ni//Bi battery (89% after 1000 cycles),[10b] Ni//Fe battery (89.1% after 1000 cycles),[3b] Ni–Co LDH//Bi 2 O 3 battery (≈93% after 1000 cycles), Ni//Zn battery (72.9% after 2400 cycles), Co 3 O 4 //Bi 2 O 3 ASCs (88% after 3000 cycles), and MnO 2 //Bi 2 O 3 ASCs (85% after 4000 cycles). [12a] The charge/discharge profiles of the Ni//Bi battery for the initial and last 5 cycles are almost the same with similar voltage plateau, again demonstrating its impressive reversibility and durability.…”

“…Furthermore, this P–Bi–C electrode presents a remarkable areal capacity of 2.11 mA h cm −2 (166.2 mA h g −1 ) at a high current density of 6 mA cm −2 , considerably outperforms the Bi–C electrode (1.07 mA h cm −2 ) and most of recently reported Bi‐based electrodes. [7,10b,12] Even at a much higher current density of 120 mA cm −2 , 56.5% of its initial capacity was still achieved, substantially better than that of the Bi–C electrode (21.3%; Figure c), demonstrating its superior rate capability. Notably, the mass loading of this P–Bi–C electrode is as high as 12.9 mg cm −2 .…”

“…Although these achievements are indeed impressive, the rate performance and cycle life of the most reported Ni//metal batteries are yet unsatisfactory (especially at high mass loading), which are caused by the intrinsically poor conductivity and sluggish kinetics of the metal oxide/hydroxide‐based electrodes. [3b,6,7] One available strategy to address these issues is to use metallic Zn nanostructures or foils to replace the metal oxide/hydroxide anode . The conductor nature of metal Zn anode can effectively promote the charge transport and ion diffusion, yielding substantially enhanced capacity and rate capability.…”

Oxygen vacancies-rich cobalt-doped NiMoO4 nanosheets for high energy density and stable aqueous Ni-Zn battery

“…As the most widely used energy storage devices commercially, lithium-ion batteries possess the advantages of high capacity, superior energy density and stable charging-discharging performance. However, the safety issues mainly caused by the unavoidable formation of lithium dendrite, as well as insufficient power density and high cost, severely hinder their further applications [4][5][6][7]. Alternatively, conventional aqueous alkaline rechargeable batteries with the merits of high safety, outstanding power density and abundant resources, have received much more attention recently, such as Ni-Fe [8,9], Ni-Co [10,11], Ni-Bi [7,12], and Ni-Zn batteries [13,14].…”

“…However, the safety issues mainly caused by the unavoidable formation of lithium dendrite, as well as insufficient power density and high cost, severely hinder their further applications [4][5][6][7]. Alternatively, conventional aqueous alkaline rechargeable batteries with the merits of high safety, outstanding power density and abundant resources, have received much more attention recently, such as Ni-Fe [8,9], Ni-Co [10,11], Ni-Bi [7,12], and Ni-Zn batteries [13,14]. Particularly, the Ni-Zn batteries hold great promise in energy storage area because of their high output voltage (~1.8 V) compared with that of other aqueous batteries (most ≤ 1.2 V), abundant reserve of Zn, and low toxicity [15,16].…”