Nanostructured Black Phosphorus/Ketjenblack–Multiwalled Carbon Nanotubes Composite as High Performance Anode Material for Sodium-Ion Batteries

Abstract

Sodium-ion batteries are promising alternatives to lithium-ion batteries for large-scale applications. However, the low capacity and poor rate capability of existing anodes for sodium-ion batteries are bottlenecks for future developments. Here, we report a high performance nanostructured anode material for sodium-ion batteries that is fabricated by high energy ball milling to form black phosphorus/Ketjenblack-multiwalled carbon nanotubes (BPC) composite. With this strategy, the BPC composite with a high phosphorus content (70 wt %) could deliver a very high initial Coulombic efficiency (>90%) and high specific capacity with excellent cyclability at high rate of charge/discharge (∼1700 mAh g(-1) after 100 cycles at 1.3 A g(-1) based on the mass of P). In situ electrochemical impedance spectroscopy, synchrotron high energy X-ray diffraction, ex situ small/wide-angle X-ray scattering, high resolution transmission electronic microscopy, and nuclear magnetic resonance were further used to unravel its superior sodium storage performance. The scientific findings gained in this work are expected to serve as a guide for future design on high performance anode material for sodium-ion batteries.

Black Phosphorus Rediscovered: From Bulk Material to Monolayers

“…[48,67,159,[169][170][171] Them ain reason for combining BP with carbon black, graphite,f ullerene,C NT,o rg raphene is to obtain more stable nanocomposites or hybrid materials,since the air stability of BP can be an enduring problem, as detailed in Section 3.2. [48,67,159,[169][170][171] Them ain reason for combining BP with carbon black, graphite,f ullerene,C NT,o rg raphene is to obtain more stable nanocomposites or hybrid materials,since the air stability of BP can be an enduring problem, as detailed in Section 3.2.…”

“…[172] As Li and Na are both alkali metals, they possess many similarities in terms of their physical and chemical properties.T he availability,l ow cost, as well as the extensive resources of Na in seawater and salt deposits makes Na the most suitable candidate for batteries based on alkali metals.S imilar to the case of LIBs,B Pr eacts electrochemically in SIBs to form crystalline Na 3 Pthrough an amorphous NaP intermediate during the sodiation process.T his is then converted back into amorphous phosphorus during the desodiation process,w ith as mall amount of amorphous NaP remaining. [160,171,173] Very promising results for BP as an anode for SIBs have recently been reported by Sun et al,w ho used ah ybrid van der Waals heterostructure made out of af ew-layers BP sandwiched between graphene layers. [160,171,173] Very promising results for BP as an anode for SIBs have recently been reported by Sun et al,w ho used ah ybrid van der Waals heterostructure made out of af ew-layers BP sandwiched between graphene layers.…”

Functionalized Hybridization of 2D Nanomaterials

“…[201] The Zn 0.5 Cd 0.5 S nanoparticles were hybridized onto the pre-produced BP nanosheets via an ultrasonic process to achieve the hydrogen production rate as high as 137.17 mmol g −1 h −1 under the irradiation of visible light, 5 times higher than that for the pristine Zn 0.5 Cd 0.5 S. [202] After enhancing the visible-light photocatalytic activity by using synthesized Z-scheme photocatalytic BP/BiVO 4 heterostructures, [204] the hydrogen and oxygen production rates were increased to ≈160 and ≈102 mmol g −1 h −1 under the irradiation of light with a wavelength longer than 420 nm. [206] Another important application of BP-based hybrids is to fabricate p-n heterojunction by combing p-type BP and n-type nanomaterials. [205] Alternatively, a ternary composite of BP, Ketjenblack and carbon nanotubes was fabricated through high-energy ball milling and further used as a anode material in sodium-ion batteries to exhibit a very high initial Coulombic efficiency (>90%) and excellent cyclability at high rate of charge/discharge.…”

Recent advances in synthesis, properties, and applications of phosphorene

“…120 Furthermore, high performance NaIB anode in the form of BP/Ketjenblack-multiwalled carbon nanotubes composite has also been recently obtained using ball milling. 121 While most of the reports on the use of phosphorene for electrochemical energy storage applications are theoretical DFT-based calculations, 11,111,112,122 some first experimental studies have also been reported, 123,124 including the work of Cui et al 97 , on the mechanism of sodiation in BP and hybrid material of few-layer phosphorene sandwiched between graphene (P/G) investigated using in-situ TEM and ex-situ XRD methods. 123 This study showed a two-step mechanism of intercalation of sodium along the x-axis followed by alloying and formation of Na 3 P. The strong anisotropic volume expansion (estimated at 0, 92, and~160%, along the x, y, and z-axis, respectively) observed in few-layer phosphorene samples was found to be suppressed in P/G nanocoposite electrodes.…”