Doctor of Philosophy, Universita Degli Studi Di Milano (2010)
MSc, Universita Degli Studi Di Milano, Industrial Chemistry (2007)
BSc, Universita Degli Studi Di Milano, Industrial Chemistry (2005)
Yi Cui, Postdoctoral Faculty Sponsor
Current Research and Scholarly Interests
Electrochemistry for energy storage and conversion
- Manganese hexacyanomanganate open framework as a high-capacity positive electrode material for sodium-ion batteries NATURE COMMUNICATIONS 2014; 5
Full open-framework batteries for stationary energy storage.
2014; 5: 3007-?
New types of energy storage are needed in conjunction with the deployment of renewable energy sources and their integration with the electrical grid. We have recently introduced a family of cathodes involving the reversible insertion of cations into materials with the Prussian Blue open-framework crystal structure. Here we report a newly developed manganese hexacyanomanganate open-framework anode that has the same crystal structure. By combining it with the previously reported copper hexacyanoferrate cathode we demonstrate a safe, fast, inexpensive, long-cycle life aqueous electrolyte battery, which involves the insertion of sodium ions. This high rate, high efficiency cell shows a 96.7% round trip energy efficiency when cycled at a 5C rate and an 84.2% energy efficiency at a 50C rate. There is no measurable capacity loss after 1,000 deep-discharge cycles. Bulk quantities of the electrode materials can be produced by a room temperature chemical synthesis from earth-abundant precursors.
View details for DOI 10.1038/ncomms4007
View details for PubMedID 24389854
A high-rate and long cycle life aqueous electrolyte battery for grid-scale energy storage
New types of energy storage are needed in conjunction with the deployment of solar, wind and other volatile renewable energy sources and their integration with the electric grid. No existing energy storage technology can economically provide the power, cycle life and energy efficiency needed to respond to the costly short-term transients that arise from renewables and other aspects of grid operation. Here we demonstrate a new type of safe, fast, inexpensive, long-life aqueous electrolyte battery, which relies on the insertion of potassium ions into a copper hexacyanoferrate cathode and a novel activated carbon/polypyrrole hybrid anode. The cathode reacts rapidly with very little hysteresis. The hybrid anode uses an electrochemically active additive to tune its potential. This high-rate, high-efficiency cell has a 95% round-trip energy efficiency when cycled at a 5C rate, and a 79% energy efficiency at 50C. It also has zero-capacity loss after 1,000 deep-discharge cycles.
View details for DOI 10.1038/ncomms2139
View details for Web of Science ID 000313514100059
View details for PubMedID 23093186
A Desalination Battery
2012; 12 (2): 839-843
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 "desalination battery", 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-x)Mn(5)O(10) 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.
View details for DOI 10.1021/nl203889e
View details for Web of Science ID 000299967800052
View details for PubMedID 22268456
- Mechanism of glucose electrochemical oxidation on gold surface ELECTROCHIMICA ACTA 2010; 55 (20): 5561-5568
- Performance of a mixing entropy battery alternately flushed with wastewater effluent and seawater for recovery of salinity-gradient energy ENERGY & ENVIRONMENTAL SCIENCE 2014; 7 (7): 2295-2300
- Nanomaterials for electrochemical energy storage FRONTIERS OF PHYSICS 2014; 9 (3): 323-350
- Full open-framework batteries for stationary energy storage NATURE COMMUNICATIONS 2014; 5
Synthesis of MoS2 and MoSe2 Films with Vertically Aligned Layers
2013; 13 (3): 1341-1347
Layered materials consist of molecular layers stacked together by weak interlayer interactions. They often crystallize to form atomically smooth thin films, nanotubes, and platelet or fullerene-like nanoparticles due to the anisotropic bonding. Structures that predominately expose edges of the layers exhibit high surface energy and are often considered unstable. In this communication, we present a synthesis process to grow MoS2 and MoSe2 thin films with vertically aligned layers, thereby maximally exposing the edges on the film surface. Such edge-terminated films are metastable structures of MoS2 and MoSe2, which may find applications in diverse catalytic reactions. We have confirmed their catalytic activity in a hydrogen evolution reaction (HER), in which the exchange current density correlates directly with the density of the exposed edge sites.
View details for DOI 10.1021/nl400258t
View details for Web of Science ID 000316243800075
- Improving the cycling stability of silicon nanowire anodes with conducting polymer coatings ENERGY & ENVIRONMENTAL SCIENCE 2012; 5 (7): 7927-7930
- Electrodeposited gold nanoparticles on carbon nanotube-textile: Anode material for glucose alkaline fuel cells ELECTROCHEMISTRY COMMUNICATIONS 2012; 19: 81-84
Tunable Reaction Potentials in Open Framework Nanoparticle Battery Electrodes for Grid-Scale Energy Storage
2012; 6 (2): 1688-1694
The electrical energy grid has a growing need for energy storage to address short-term transients, frequency regulation, and load leveling. Though electrochemical energy storage devices such as batteries offer an attractive solution, current commercial battery technology cannot provide adequate power, and cycle life, and energy efficiency at a sufficiently low cost. Copper hexacyanoferrate and nickel hexacyanoferrate, two open framework materials with the Prussian Blue structure, were recently shown to offer ultralong cycle life and high-rate performance when operated as battery electrodes in safe, inexpensive aqueous sodium ion and potassium ion electrolytes. In this report, we demonstrate that the reaction potential of copper-nickel alloy hexacyanoferrate nanoparticles may be tuned by controlling the ratio of copper to nickel in these materials. X-ray diffraction, TEM energy dispersive X-ray spectroscopy, and galvanostatic electrochemical cycling of copper-nickel hexacyanoferrate reveal that copper and nickel form a fully miscible solution at particular sites in the framework without perturbing the structure. This allows copper-nickel hexacyanoferrate to reversibly intercalate sodium and potassium ions for over 2000 cycles with capacity retentions of 100% and 91%, respectively. The ability to precisely tune the reaction potential of copper-nickel hexacyanoferrate without sacrificing cycle life will allow the development of full cells that utilize the entire electrochemical stability window of aqueous sodium and potassium ion electrolytes.
View details for DOI 10.1021/nn204666v
View details for Web of Science ID 000300757900079
View details for PubMedID 22283739
Symmetrical MnO2-Carbon Nanotube-Textile Nanostructures for Wearable Pseudocapacitors with High Mass Loading
2011; 5 (11): 8904-8913
While MnO(2) is a promising material for pseudocapacitor applications due to its high specific capacity and low cost, MnO(2) electrodes suffer from their low electrical and ionic conductivities. In this article, we report a structure where MnO(2) nanoflowers were conformally electrodeposited onto carbon nanotube (CNT)-enabled conductive textile fibers. Such nanostructures effectively decrease the ion diffusion and charge transport resistance in the electrode. For a given areal mass loading, the thickness of MnO(2) on conductive textile fibers is much smaller than that on a flat metal substrate. Such a porous structure also allows a large mass loading, up to 8.3 mg/cm(2), which leads to a high areal capacitance of 2.8 F/cm(2) at a scan rate of 0.05 mV/s. Full cells were demonstrated, where the MnO(2)-CNT-textile was used as a positive electrode, reduced MnO(2)-CNT-textile as a negative electrode, and 0.5 M Na(2)SO(4) in water as the electrolyte. The resulting pseudocapacitor shows promising results as a low-cost energy storage solution and an attractive wearable power.
View details for DOI 10.1021/nn203085j
View details for Web of Science ID 000297143300051
View details for PubMedID 21923135
- Lithium-Ion Textile Batteries with Large Areal Mass Loading ADVANCED ENERGY MATERIALS 2011; 1 (6): 1012-1017
- Nano-structured textiles as high-performance aqueous cathodes for microbial fuel cells ENERGY & ENVIRONMENTAL SCIENCE 2011; 4 (4): 1293-1297
Batteries for Efficient Energy Extraction from a Water Salinity Difference
2011; 11 (4): 1810-1813
The salinity difference between seawater and river water is a renewable source of enormous entropic energy, but extracting it efficiently as a form of useful energy remains a challenge. Here we demonstrate a device called "mixing entropy battery", which can extract and store it as useful electrochemical energy. The battery, containing a Na(2-x)Mn(5)O(10) nanorod electrode, was shown to extract energy from real seawater and river water and can be applied to a variety of salt waters. We demonstrated energy extraction efficiencies of up to 74%. Considering the flow rate of river water into oceans as the limiting factor, the renewable energy production could potentially reach 2 TW, or ?13% of the current world energy consumption. The mixing entropy battery is simple to fabricate and could contribute significantly to renewable energy in the future.
View details for DOI 10.1021/nl200500s
View details for Web of Science ID 000289341500074
View details for PubMedID 21413685
- Optimizing operating conditions and electrochemical characterization of glucose-gluconate alkaline fuel cells JOURNAL OF POWER SOURCES 2011; 196 (3): 1273-1278
Three-Dimensional Carbon Nanotube-Textile Anode for High-Performance Microbial Fuel Cells
2011; 11 (1): 291-296
Microbial fuel cells (MFCs) harness the metabolism of microorganisms, converting chemical energy into electrical energy. Anode performance is an important factor limiting the power density of MFCs for practical application. Improving the anode design is thus important for enhancing the MFC performance, but only a little development has been reported. Here, we describe a biocompatible, highly conductive, two-scale porous anode fabricated from a carbon nanotube-textile (CNT-textile) composite for high-performance MFCs. The macroscale porous structure of the intertwined CNT-textile fibers creates an open 3D space for efficient substrate transport and internal colonization by a diverse microflora, resulting in a 10-fold-larger anolyte-biofilm-anode interfacial area than the projective surface area of the CNT-textile. The conformally coated microscale porous CNT layer displays strong interaction with the microbial biofilm, facilitating electron transfer from exoelectrogens to the CNT-textile anode. An MFC equipped with a CNT-textile anode has a 10-fold-lower charge-transfer resistance and achieves considerably better performance than one equipped with a traditional carbon cloth anode: the maximum current density is 157% higher, the maximum power density is 68% higher, and the energy recovery is 141% greater.
View details for DOI 10.1021/nl103905t
View details for Web of Science ID 000286029400050
View details for PubMedID 21158405
- A new approach to glucose sensing at gold electrodes ELECTROCHEMISTRY COMMUNICATIONS 2010; 12 (10): 1407-1410
- Aqueous supercapacitors on conductive cotton NANO RESEARCH 2010; 3 (6): 452-458
Stretchable, Porous, and Conductive Energy Textiles
2010; 10 (2): 708-714
Recently there is strong interest in lightweight, flexible, and wearable electronics to meet the technological demands of modern society. Integrated energy storage devices of this type are a key area that is still significantly underdeveloped. Here, we describe wearable power devices using everyday textiles as the platform. With an extremely simple "dipping and drying" process using single-walled carbon nanotube (SWNT) ink, we produced highly conductive textiles with conductivity of 125 S cm(-1) and sheet resistance less than 1 Omega/sq. Such conductive textiles show outstanding flexibility and stretchability and demonstrate strong adhesion between the SWNTs and the textiles of interest. Supercapacitors made from these conductive textiles show high areal capacitance, up to 0.48F/cm(2), and high specific energy. We demonstrate the loading of pseudocapacitor materials into these conductive textiles that leads to a 24-fold increase of the areal capacitance of the device. These highly conductive textiles can provide new design opportunities for wearable electronics and energy storage applications.
View details for DOI 10.1021/nl903949m
View details for Web of Science ID 000274338800059
View details for PubMedID 20050691