Titanium Diboride-Based Hierarchical Nanosheets as Anode Material for Li-Ion Batteries

Abstract

Two-dimensional (2D) materials are enabling us to pursue several exciting avenues to enhance the performance of electrochemical energy-storage devices. Particularly, 2D nanostructures based on transition-metal diborides (TMDs) are theoretically predicted to possess an exceptionally high rate and long cycling stability for Li-ion storage owing to the intrinsic presence of boron honeycomb planes and multivalent transition-metal atoms. In this study, we present the first experimental investigation of the Li-ion storage potential of one such TMD-based nanostructure–titanium diboride (TiB2)-based hierarchical nanosheets (THNS). We demonstrate that THNS can be utilized as a high-rate anode material for Li-ion battery (LIB) and that a discharge capacity as high as ∼380 mA h g–1 can be obtained at a current rate of 0.025 A g1– galvanostatic charge/discharge. Further, a discharge capacity of 174 mA h g–1 can be obtained at a current rate of 1 A g1– (charge time of ∼10 min) with a capacity retention of 89.7% after 1000 cycles. We also demonstrate that the THNS-based LIB anode can sustain extremely high current rates (15 to 20 A g1–) allowing ultrafast charging in 9–14 s, and considerable discharge capacity (50 to 60 mA h g–1) with a capacity retention of over 80% after 10 000 cycles. We also present some insights into the charge-storage characteristics of THNS-based anodes using ex situ electrochemical field emission scanning electron microscopy and X-ray photoemission spectroscopy measurements.

Nitrogen adsorption via charge transfer on vacancies created during surfactant assisted exfoliation of TiB2

“…3b), with the maximum value of 5.5 mg −1 cm −1 mL at 200 nm. 20,35 This value is comparable with that of functionalized TiB 2 nanosheets ( ε 270 = 3.48 mg −1 cm −1 mL) but an order of magnitude lesser than that of other 2D materials (graphene, WS 2 , h-BN, and MoS 2 ), suggesting that these nanosheets are more transparent than other 2D materials. 20,50–52 To assess how the surfactant concentration ( C S ) influences the concentration of nanosheets ( C N ), we measured C N values in final dispersions for C S values ranging from 1 to 5 g l −1 .…”

“…33 Although both these approaches successfully converted TiB 2 into its quasi-2D form, the resultant nanosheets were heavily functionalized. While functionalization endowed distinct advantages to these nanosheets, [34][35][36][37] it also significantly altered the chemical structure of TiB 2 . An approach that preserves the long-range crystallinity of TiB 2 and minimizes functionalization upon nanoscaling would facilitate an enhanced access to the planes of titanium and boron, which is otherwise challenging to achieve.…”

Quasi-Two-Dimensional Nanostructures from AlB2-Type Metal Borides: Physicochemical Insights and Emerging Trends

“…These TiB 2 nanosheets have also been used as anode materials for Li-ion batteries. 65 The anode material with the nanosheets could sustain very high current rates and also demonstrated highcapacity retention of 80% even after 10000 cycles enabling ultrafast charging. The authors put forward the hierarchical nature of these nanosheets as a pivotal feature for their enhanced performance as anode material.…”

“…This study exemplifies the rich potential of TiB 2 nanosheets as an anode material for sodium-ion batteries. These TiB 2 nanosheets have also been used as anode materials for Li-ion batteries . The anode material with the nanosheets could sustain very high current rates and also demonstrated high-capacity retention of 80% even after 10000 cycles enabling ultrafast charging.…”

“…(C) Long cycle life of TiB 2 nanosheet-based anode material, showing high discharge capacities at higher current rates ranging from 15 to 20 A g –1 . Reprinted with permission from ref . Copyright 2022, American Chemical Society.…”