Monovalent manganese based anodes and co-solvent electrolyte for stable low-cost high-rate sodium-ion batteries

Abstract

The demand of sustainable power supply requires high-performance cost-effective energy storage technologies. Here we report a high-rate long-life low-cost sodium-ion battery full-cell system by innovating both the anode and the electrolyte. The redox couple of manganese(I/II) in Prussian blue analogs enables a high-rate and stable anode. Soft X-ray absorption spectroscopy and resonant inelastic X-ray scattering provide direct evidence suggesting the existence of monovalent manganese in the charged anode. There is a strong hybridization between cyano ligands and manganese-3d states, which benefits the electronic property for improving rate performance. Additionally, we employ an organic–aqueous cosolvent electrolyte to solve the long-standing solubility issue of Prussian blue analogs. A full-cell sodium-ion battery with low-cost Prussian blue analogs in both electrodes and co-solvent electrolyte retains 95% of its initial discharge capacity after 1000 cycles at 1C and 95% depth of discharge. The revealed manganese(I/II) redox couple inspires conceptual innovations of batteries based on atypical oxidation states.

A Heterostructure Coupling of Bioinspired, Adhesive Polydopamine, and Porous Prussian Blue Nanocubics as Cathode for High‐Performance Sodium‐Ion Battery

“…[ 4–8 ] Among these, the sodium‐ion batteries (SIBs) have received growing research attention, on account of the inexhaustible and low‐cost nature of sodium resource, as well as its suitable redox potential and safety. [ 9–12 ]…”

Recent research progresses in ether‐ and ester‐based electrolytes for sodium‐ion batteries

“…As a result, improved sodium storage performance has been observed in a variety of anode materials, after using ester‐based electrolytes rather than its ether analogue . Cohn et al demonstrated that highly crystalline few‐layered graphene can act as an ultrafast Na‐ion anode in NaPF 6 ‐diglyme system, where a diglyme solvent shell is able to encapsulate a sodium ion as “nonstick” coating to help rapid ion insertion (Figure A,B).…”

“…75 As a result, improved sodium storage performance has been observed in a variety of anode materials, after using ester-based electrolytes rather than its ether analogue. [76][77][78][79][80][81] Cohn et al 76 demonstrated that highly crystalline few-layered graphene can act as an ultrafast Na-ion anode in NaPF 6diglyme system, where a diglyme solvent shell is able to encapsulate a sodium ion as "nonstick" coating to help rapid ion insertion ( Figure 5A,B). Xu's research group 77 developed a novel strategy of decoupling the merits of ester-and ether-based electrolytes to enable HC anode with superior cycle performance ( Figure 5C).…”

Understanding Challenges of Cathode Materials for Sodium‐Ion Batteries using Synchrotron‐Based X‐Ray Absorption Spectroscopy

“…(j) Mn L 3 ‐edge sXAS spectra (left) and N K‐edge sXAS spectra (right) at different states of charge. Reprinted with permission from (i)–(j) . Copyright 2018 Springer Nature.…”