A Desalination Battery

Water desalination is an important approach to provide fresh water around the world, although its high energy consumption, and thus high cost, call for new, efficient technology. Here, we demonstrate the novel concept of a “<i>desalination battery</i>”, which operates by performing cycles in reverse on our previously reported mixing entropy battery. Rather than generating electricity from salinity differences, as in mixing entropy batteries, desalination batteries use an electrical energy input to extract sodium and chloride ions from seawater and to generate fresh water. The desalination battery is comprised by a Na_2‑xMn₅O₁₀ nanorod positive electrode and Ag/AgCl negative electrode. Here, we demonstrate an energy consumption of 0.29 Wh l^–1 for the removal of 25% salt using this novel desalination battery, which is promising when compared to reverse osmosis (∼ 0.2 Wh l^–1), the most efficient technique presently available

Chemical Intercalation of Zerovalent Metals into 2D Layered Bi₂Se₃ Nanoribbons

We have developed a chemical method to intercalate a variety of zerovalent metal atoms into two-dimensional (2D) layered Bi₂Se₃ chalcogenide nanoribbons. We use a chemical reaction, such as a disproportionation redox reaction, to generate dilute zerovalent metal atoms in a refluxing solution, which intercalate into the layered Bi₂Se₃ structure. The zerovalent nature of the intercalant allows superstoichiometric intercalation of metal atoms such as Ag, Au, Co, Cu, Fe, In, Ni, and Sn. We foresee the impact of this methodology in establishing novel fundamental physical behaviors and in possible energy applications

High-Density Chemical Intercalation of Zero-Valent Copper into Bi₂Se₃ Nanoribbons

A major goal of intercalation chemistry is to intercalate high densities of guest species without disrupting the host lattice. Many intercalant concentrations, however, are limited by the charge of the guest species. Here we have developed a general solution-based chemical method for intercalating extraordinarily high densities of zero-valent copper metal into layered Bi₂Se₃ nanoribbons. Up to 60 atom % copper (Cu_7.5Bi₂Se₃) can be intercalated with no disruption to the host lattice using a solution disproportionation redox reaction

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

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