Bi³⁺ Induced Crystal Growth of a Symbiotic Heterojunction Enables Long‐Lifespan Zn‐Ion Batteries

Abstract

The MnO 2 /Mn 2 O 3 symbiotic heterojunction is considered to be a promising cathode material for aqueous zinc-ion batteries (ZIBs) owing to the built-in electric field generated from the heterojunction interface that can accelerate ion transporting. However, the structure collapse caused by the Mn 3 + dissolution, leading to a sharp capacity decline, is still one of the major issues. In this work, a Bi-doped MnO 2 /Mn 2 O 3 symbiotic heterojunction with a uniform nanorod structure was formed due to the Bi-induced crystal growth mechanism. In addition, Bi 3 + doped into the lattice effectively inhibited the dissolution of Mn 3 + and greatly enhanced charge transfer and reaction kinetics. Therefore, an impressive long-term cycling performance over 6000 cycles at a current density of 2 A g À 1 was obtained. Such a Bi 3 + induced symbiotic heterojunction crystal growth strategy may open new opportunities toward highperformance aqueous ZIBs.

A topochemical reaction induced the formation of Bi2S3 micro-straws from a Bi-MOF for an ultra-long Zn storage life

“…The EIS fitting results show the corresponding R ct values of 5.47, 5.98, 7.08, and 16.79 Ω for Bi 2 S 3 -TH, Bi 2 S 3 -TR1, Bi 2 S 3 -TR2, and Bi 2 S 3 -TF, respectively. In addition, the slope of the oblique line in the low frequency region was further analyzed using the following formula: 60 where R represents the gas constant (8.314 J k −1 mol −1 ), T is the absolute temperature (298 K), A means the surface area of the electrode (1.76 cm 2 ), N is the number of electron transfers, F is the Faraday constant (96 500 C mol −1 ), C means the ion concentration (3 mol L −1 ), and σ is the Warburg coefficient in the low-frequency region, which can be determined using the following equation: 60 Z re = R s + R ct + σω −0.5 where Z re is the real part of the impedance, R ct represents the charge transfer resistance, and ω is the angular frequency, which is related to the frequency of the low-frequency region. The calculated ionic diffusion coefficient of Bi 2 S 3 -TH is 1.14 × 10 −10 cm 2 s −1 (Table S1†), which is much larger than those of Bi 2 S 3 -TR1 (3.32 × 10 −11 cm 2 s −1 ), Bi 2 S 3 -TR2 (3.46 × 10 −11 cm 2 s −1 ) and Bi 2 S 3 -TF (1.16 × 10 −11 cm 2 s −1 ).…”

“…3d), implying that surface-controlled capacitive behavior and faradaic intercalation synergistically dominate the charge-storage process. The contribution of the capacitance effect ( k 1 υ ) and diffusion effect ( k 2 υ 1/2 ) can be assessed according to the following formula: 60 i ( υ ) = k 1 υ + k 2 υ 1/2 …”

One‐Step Cooperative Growth of High Reaction Kinetics Composite Homogeneous Core–Shell Heterostructure

“…The enhanced electronic interaction between the various components is benefit to structural stability and the reaction kinetics, which favors better electrochemical properties. [30,31]…”

“…Inspired by the excellent performance of the collaborative growth in metal eutectic alloys, [27][28][29] this study aims to prepare composite electrode materials through symbiotic growth to enhance the coupling action between different components. Gou et al [30] synthesized a bismuth-doped MnO 2 /Mn 2 O 3 symbiotic heterojunction by a one-step hydrothermal process. The MnO 2 /Mn 2 O 3 symbiotic heterojunction with uniform morphology and multi-phase coexistence could accelerate the ion transport rate through the built-in electric field generated by the interface because of its tighter interface contact and improve the reaction kinetics of ion intercalation and deintercalation.…”