Revealing the Real Charge Carrier in Aqueous Zinc Batteries Based on Polythiophene/Manganese Dioxide Cathode

Abstract

Developing sustainable and clean energy (solar, wind, tidal energy, etc.) is a significant way to solve the increasing energy crisis and environmental problems. [1,2] However, sustainable and clean energies are difficult to stabilize supply due to their significant instability and randomness, which require grid-scale energy storage equipment to achieve stable and continuous energy output. [3][4][5] Benefiting from the high energy density and long cycling life, the energy storage market is dominated by lithium-ion battery systems. [6] Unfortunately, its development is faced by many problems, such as safety risks associated with organic electrolytes and high costs originating from low-lithium resource reserves, limiting its application in grid-scale energy storage. [6,7] It is urgent to develop a new battery system to meet growing energy storage needs. Recently, aqueous batteries are expected to be the most promising candidates for next-generation energy storage devices with the advantages of high energy density and safety, low cost, and environmental friendliness. [2,8] In diverse aqueous batteries, aqueous zinc batteries (AZBs) are the eye-catching battery systems due to the high theoretical capacity (mass-specific capacity: 820 mAh g À1 , volume-specific capacity: 5848 mAh cm À3 ), comparatively low redox potential (À0.76 V vs. standard hydrogen electrode), and highly stable chemistry of zinc anode in mild electrolyte. [9][10][11][12] Meanwhile, the cathode materials of AZBs have the advantages of low costs, rich resources, diversity, high safety, and environmental friendliness. [4,5,[13][14][15] Therefore, AZBs become the most potential battery system candidates to replace traditional lithium-ion batteries in power batteries and grid-scale energy storage.

Sulfur-Defect-Induced TiS1.94 as a High-Capacity and Long-Life Anode Material for Zinc-Ion Batteries

“…Interestingly in both electrodes, the first three CV curves almost overlap, implying the superior structural stability of TiS 2 upon Zn 2+ insertion/extraction. 49 Figure 3b presents the original charge/discharge profiles drawn by both TiS 2 and D-TiS 1.94 from 0.05 to 0.7 V (vs Zn 2+ /Zn) at 0.05 A g −1 . Both cathodes exhibit three distinct discharge/charge voltage plateaus, agreeing well with the CV redox peaks in Figure 3a, which is related to the multiple Zn 2+ insertion/extraction processes at different sites.…”

2D Layered MnO2 with an Ultralarge Interlayer Spacing for Aqueous Zinc Ion Batteries

“…However, the electrochemical performance of δ-MnO 2 in AZIBs is severely limited by sluggish reaction kinetics, inferior structural stability, intense electrostatic interactions, and poor electronic conductivity. 7 To overcome these problems, researchers have proposed various strategies, including nanostructure design, 8,9 composites with conductive polymers, 10 preintercalation, 11−15 and defect engineering, 16 to improve the electrochemical performance of δ-MnO 2 cathodes. In particular, the preintercalation strategy has proven to be a fundamental and highly effective approach for enhancing the capacity, cycle stability, and rate capability of a δ-MnO 2 cathode.…”

“…To overcome these problems, researchers have proposed various strategies, including nanostructure design, , composites with conductive polymers, preintercalation, − and defect engineering, to improve the electrochemical performance of δ-MnO 2 cathodes. In particular, the preintercalation strategy has proven to be a fundamental and highly effective approach for enhancing the capacity, cycle stability, and rate capability of a δ-MnO 2 cathode. , Preintercalated ions or molecules play a crucial role in increasing the interlayer spacing, facilitating ion transfer, and serving as “structural pillars” to prevent structural collapse. − Meanwhile, preintercalation can efficiently fine-tune the electronic structure of the host materials, leading to significant acceleration of electron-transfer processes. − Various ions and molecules have been previously investigated, including alkali ions, ,− NH 4 + , tetramethylammonium, Cu 2+ , Zn 2+ , Ba 2+ , La 3+ , Sn 4+ , Mo 4+ , and polyaniline .…”

Regeneration of Spent Lithium Manganate Batteries into Al-Doped MnO2 Cathodes toward Aqueous Zn Batteries

“…33,34 Nevertheless, the research of high-performance MnO 2 still encounters significant barriers due to its structural instability and manganese dissolution, impeding its actual applications. To solve these issues, tremendous efforts, such as heteroatoms doping, 35−37 surface engineering, 38 defect engineering, 39,40 and electrolyte modification, 41−43 have been devoted to improving its electrochemical performance. Heteroatoms doping can enhance the stability of manganese dioxide skeleton and avoid excessive dissolved deposition of manganese dioxide.…”

“…It is more favorable to give higher capacity than MnO 2 with other crystalline forms. , Nevertheless, the research of high-performance MnO 2 still encounters significant barriers due to its structural instability and manganese dissolution, impeding its actual applications. To solve these issues, tremendous efforts, such as heteroatoms doping, − surface engineering, defect engineering, , and electrolyte modification, − have been devoted to improving its electrochemical performance. Heteroatoms doping can enhance the stability of manganese dioxide skeleton and avoid excessive dissolved deposition of manganese dioxide. , Since the atomic radius of Al 3+ (53.5 pm) is comparable to that of Mn 4+ (53 pm), it has been suggested that aluminum can replace Mn or occupy the tunnels of MnO 2 more easily. − Furthermore, it is reported that aluminum doping can also increase the conductivity of manganese dioxide …”