Cu₁₂Sb₄S₁₃ Quantum Dots/Few‐Layered Ti₃C₂ Nanosheets with Enhanced K⁺ Diffusion Dynamics for Efficient Potassium Ion Storage

Abstract

Despite the high theoretical specific capacity of transition-metal disulfides anode for potassium-ion batteries (PIBs), their development has been greatly hindered by dramatic capacity fading and poor cycle life. Herein, the synthesis of the new composite of Cu 12 Sb 4 S 13 quantum dots/few-layered Ti 3 C 2 nanosheets (CAS-Ti 3 C 2 ) as advanced anode for boosting the K ion storage is reported. It is found that as-made CAS-Ti 3 C 2 show a strong synergistic effect between quantum dots and Ti 3 C 2 nanosheets mainly caused by the formation of the Ti-S bond, which can not only shorten the diffusion path of K + but also accommodate the serious volumetric variation during the discharge/charge process. As expected, this specially designed CAS-Ti 3 C 2 anode exhibits a superior reversible specific capacity of 496.7 mAh g −1 at 100 mA g −1 after 200 cycles and 175.6 mAh g −1 at a high current density of 1.0 A g −1 even over 1800 cycles, preceding most of the reported transition-metal disulfides quantum dots-based anodes for PIBs. These comprehensive studies reveal that the excellent electrochemical property is attributed to the fast K + diffusion kinetics and unique transformation and restorage mechanism between K + with CAS-Ti 3 C 2 anode.

Electrochemical Self‐Healing Nanocrystal Electrodes for Ultrastable Potassium‐Ion Storage

“…The long-term cycle performance of the previously reported ternary chalcogenide-based (such as CuSbS 2 , FeCoS 2 , BiSbS 3, and AgBiS 2 ) has not exceeded 1000 cycles, except Cu 12 Sb 4 S 13 (Figure 2i). [4,[40][41][42][43] To confirm the phase transition of the Cu 3 BiS 3 electrode during the charging/discharging process, ex situ XRD analysis was performed at six different potentials, as shown in Figure 3a and Table S1 (Supporting Information). First, it can be observed that some fixed peaks are attributed to Al foil, and partially oxidized CuO .…”

Semiconducting Quantum Dots for Energy Conversion and Storage

“…Moreover, the synthesis of the Cu 12 Sb 4 S 13 QDs/Ti 3 C 2 (CAS-Ti 3 C 2 ) as novel anode for improving the K + storage was presented. [140] The as-obtained CAS-Ti 3 C 2 exhibited a strong synergistic effect due to the formation of TiS bond (Figure 4e,f), and then the diffusion path of K + can be shortened (Figure 4g) as well as alleviating the volumetric expansion during the charging-discharging process. Therefore, this novel composite anode shows a remarkable reversible specific capacity as well as excellent cycling performance for Potassium-ion batteries (PIBs).…”

“…Moreover, developing bimetal sulfide QDsbased anodes for PIBs can promote its cycle life. Cao et al [140] reported the synthesis of Cu 12 Sb 4 S 13 QDs/Ti 3 C 2 nanosheets (CAS-Ti 3 C 2 ) composite as anode for improving the potassium storage (Figure 22g-i). The composite showed a synergistic effect between QDs and Ti 3 C 2 sheets due to the presence of TiS bond, which can significantly shortened the diffusion path of K + and suppressed the volume change during the cycling reaction.…”

“…g) Separation of pseudocapacitive (white part) and diffusion (blue part) controlled contribution at different scan rates for the CAS-Ti 3 C 2 composites. Reproduced with permission [140]. Copyright 2021, Wiley-VCH GmbH.…”

“…h,i) Electrochemical performance of CAS-Ti 3 C 2 anode for PIBs: (h) charge-discharge curves of CAS-Ti 3 C 2 , and (i) rate performance of CAS-Ti 3 C 2 composites, Cu 12 Sb 4 S 13 QDs, and Ti 3 C 2 nanosheets. Reproduced with permission [140]. Copyright 2021, Wiley-VCH GmbH.…”