Alloyed BiSb Nanoparticles Confined in Tremella‐Like Carbon Microspheres for Ultralong‐Life Potassium Ion Batteries

Abstract

Bismuth-antimony alloy is considered as a promising potassium ion battery anode because of its combination of the high theoretical capacity of antimony and the excellent rate capacity of bismuth. However, the large volume change and sluggish reaction kinetic upon cycling have triggered severe capacity fading and poor rate performance. Herein, a nanoconfined BiSb in tremellalike carbon microspheres (BiSb@TCS) are delicately designed to address these issues. As-prepared BiSb@TCS renders an outstanding potassiumstorage performance with a reversible capacity of 181 mAh g −1 after ultralong 5700 cycles at a current density of 2 A g −1 , and an excellent rate capacity of 119.3 mAh g −1 at 6 A g −1 . Such a superior performance can be ascribed to the delicate microstructure. The self-assembled carbon microspheres can strengthen integral structure and effectively accommodate the volume expansion of BiSb nanoparticles, and 2D carbon nanowalls in carbon microspheres can provide fast ion/electron diffusion dynamic. Theoretical calculation also suggests a thermodynamic feasibility of alloyed BiSb nanoparticles for storing potassium ion. Such a work shows that BiSb@TCS possesses a great potential to be a high-performance anode of potassium ion batteries. The rational designing of multiscaled structure would be instructive to the exploitation of other energy-storage materials.

Structure Engineering of BiSbSx Nanocrystals Embedded within Sulfurized Polyacrylonitrile Fibers for High Performance of Potassium‐Ion Batteries

“…Surprisingly, an exceptional reversible capacity of 790 mAh g −1 is reached for the BiSbS x @SPAN‐450 electrode after 50 cycles. To the best of our knowledge, the BiSbS x @SPAN‐450 electrode shows one of the best performances as a PIBs anode electrode for metal dichalcogenides in terms of reversible capacity (Table S1) [4,23,25,48,53–58] . In addition, the rate performance of BiSbS x @SPAN‐450 was studied at current densities ranging from 0.2 A g −1 to 2 A g −1 (Figure 4b), and the results obtained were found to be outstanding compared to the other electrodes.…”

“…for metal dichalcogenides in terms of reversible capacity (Table S1). [4,23,25,48,[53][54][55][56][57][58] In addition, the rate performance of BiSbS x @SPAN-450 was studied at current densities ranging from 0.2 A g À 1 to 2 A g À 1 (Figure 4b), and the results obtained were found to be outstanding compared to the other electrodes. The BiSbS x @SPAN-450 electrode maintains decent reversible capacities of 601, 489 and 393 mAh g À 1 at 0.2, 1 and 2 A g À 1 , respectively.…”

Bean Pod‐Like SbSn/N‐Doped Carbon Fibers toward a Binder Free, Free‐Standing, and High‐Performance Anode for Sodium‐Ion Batteries

“…As shown in Figure 3b, the thermogravimetric analysis (TGA) of B-SbSn/NCFs was carried out, illustrating that the first loss of weight (5.03%) was the evaporation of the water absorbed by the sample. The mass proportion of active substance SbSn in the B-SbSn/NCFs was 51.4%, and was calculated by the following equation [41,42] SbSn O Sb O SnO Through the nitrogen adsorption-specific surface area test, the adsorption and desorption of gas under different pressures were measured. The Brunauer-Emmett-Teller (BET) method and Barrett-Joyner-Halenda method were used to calculate the specific surface area and pore size distribution of the sample.…”

Sulfur/Nitrogen Co‐Doped In‐Plane Porous Carbon Nanosheets as Superior Anode of Potassium‐Ion Batteries

“…GITT measurement was utilized to assess the diffusion coefficients ( D k ) of potassium in SN‐CNSs electrode and control sample of CNSs electrode by applying a series of current pulses at 0.5 A g −1 for 2 min followed by a 10 min relaxation process (Figures 4f and S15). The function was introduced to calculate the value of D k based on Equation 1: [55] …”