Zn-Ion Batteries: Boosting the Rate Capability and Low-temperature Performance by Combining Structure and Morphology Engineering

Abstract

Prussian blue analogues (PBAs) have been considered as one kind of the most promising cathode materials for Zn-ion batteries (ZIBs) due to their low cost, high performance, high safety, and high abundance. However, owing to the low conductivity and single electron reaction, it is a great challenge to obtain a PBA cathode material with high reversible capacity, high rate capability, and good temperature adaptability. Here, a cathode material, K1.14(VO)3.33[Fe­(CN)6]2·6.8H2O (KVHCF), with a multielectron reaction and double conductive carbon framework (DCCF) is designed and synthesized by combining structure and morphology engineering. With the multielectron reaction and high electronic conductivity simultaneously, the KVHCF@DCCF cathode material delivers a high specific capacity (180 mAh·g–1 @ 400 mA·g–1) and the best rate performance (116 mAh·g–1 @ 8000 mA·g–1) of the reported PBAs. Moreover, KVHCF@DCCF presents a high specific capacity of 132 mAh·g–1 @ 400 mA·g–1 at 0 °C. Even at −10 °C, it still delivers specific capacities of 127 mAh·g–1 @ 40 mA·g–1 and 80 mAh·g–1 @ 400 mA·g–1 with a retention of 86% after 700 cycles. In situ X-ray diffraction (XRD) and ex situ X-ray photoelectron spectroscopy (XPS) are carried out to investigate the charge–discharge electrochemical reaction mechanism.

Revisiting Charge Storage Mechanism of Reduced Graphene Oxide in Zinc Ion Hybrid Capacitor beyond the Contribution of Oxygen‐Containing Groups

“…However, the development of proper cathode materials that match with Zn anode well remains challenging. To date, a number of cathode materials, including organic compounds, [17] metal-organic frameworks (MOFs), [18,19] covalent-organic frameworks (COFs), [20,21] and carbonaceous materials, [22][23][24][25] have been reported. Comparably, rGO is considered the most promising one owing to the 2D graphitic structure, tailorable surface functionalities (e.g., oxygen-containing groups), adjustable interlayer spacing, and good physiochemical and electrochemical stability.…”

Zn3V4(PO4)6: A New Rocking-Chair-Type Cathode Material with High Specific Capacity Derived from Zn2+/H+ Cointercalation for Aqueous Zn-Ion Batteries

“…Phosphate materials generally have low electronic conductivity . In order to increase the electronic conductivity, in situ high-temperature carbonization carbon coating and ex situ ball-milling carbon coating are applied at the same time. , The carbon-coating effect was verified by Raman spectrum (Figure c).…”

“…The GITT test (Figure 4d and Figure S13) shows that ZVP@C/30%BP has a high ion transport coefficient (10 −13 ∼10 −9 s•cm −2 ), comparable to those with a fast ion conductor structure. 11 All these results prove the enhanced electrochemical activation, high electronic conductivity, low charge transfer resistance, and high ion diffusion rate derived from the carbon coating, which results in better electrochemical performance of ZVP@C/30% BP than that of ZVP@C.…”

“…Aqueous zinc-ion batteries (AZIBs) have attracted extensive attention due to their high reserves, low cost, and high safety. , The research of AZIBs is in its infancy and focused on the design and search for appropriate cathode materials. , Although the size of Zn 2+ is close to that of Li + , its high polarization (two charges) leads to strong electrostatic attraction between Zn 2+ and the skeleton structure of the host, resulting in low ion diffusion ability and migration dynamics. , Currently, the main cathode materials for AZIBs are manganese oxides, , vanadium oxides, , and Prussian blue analogues (PBAs) . However, they still have some deficiencies in specific capacity, rate performance, and stability, which seriously limit their wide application.…”

“…5,6 Currently, the main cathode materials for AZIBs are manganese oxides, 7,8 vanadium oxides, 9,10 and Prussian blue analogues (PBAs). 11 However, they still have some deficiencies in specific capacity, rate performance, and stability, which seriously limit their wide application.…”