A semi-solid flow battery, also known as a semi-solid state battery, is a type of flow battery using solid battery active materials or involving solid species in the energy carrying fluid. A research team in MIT proposed this concept using lithium-ion battery materials. [2] In such a system, both positive (cathode) and negative electrode (anode) consist of active material particles with carbon black suspended in liquid electrolyte. Active material suspensions are stored in two energy storage tanks. The suspensions are pumped into the electrochemical reaction cell when charging and discharging. This design takes advantage of both the designing flexibility of flow batteries and the high energy density active materials of lithium-ion batteries.
Two different flow modes were explored, intermittent flow mode and continuous flow mode. In an intermittent flow mode, suspensions are pumped into the electrochemical reaction cell in a batch basis and a new batch is pumped in only after the previous batch has been fully charged/discharged. In a continuous flow mode, however, the suspensions are continuously pumped through the electrochemical reaction cell during the charge/discharge process. By using lithium-ion battery active materials, the energy density of the flow battery system can be significantly improved. An aqueous system was also demonstrated besides the organic one. [3] Other chemistries have also been explored for this system, such as sodium-ion battery, lithium-sulfur battery, and others.
Despite the significant advantage of such a system, one key limitation was the high viscosity, which makes the power consumption for pumping very high, hence decreasing the energy efficiency. Another research team in University of Virginia reported a carbon-free flow battery system. [5] In this new system, also called Solid Dispersion Flow Battery, a new reaction mechanism was discovered with electrochemical reactions occurring based on particle collisions. [6]
Another approach is to pump the liquid phase only, leaving the solid active materials in the energy storage tanks. A research group reported redox targeting flow battery. [8] There are redox targeting materials dissolved in the electrolyte and electrochemical reactions occur between the dissolved species. The solid materials are then been chemically oxidized or reduced. By keeping solid materials in the tanks, only the liquid electrolyte is being pumped. This saves the pumping energy although the voltage efficiency is sacrificed. [9]
An electrode is an electrical conductor used to make contact with a nonmetallic part of a circuit. Electrodes are essential parts of batteries that can consist of a variety of materials (chemicals) depending on the type of battery.
An electrochemical cell is a device that generates electrical energy from chemical reactions. Electrical energy can also be applied to these cells to cause chemical reactions to occur. Electrochemical cells that generate an electric current are called voltaic or galvanic cells and those that generate chemical reactions, via electrolysis for example, are called electrolytic cells.
A lithium-ion or Li-ion battery is a type of rechargeable battery that uses the reversible intercalation of Li+ ions into electronically conducting solids to store energy. In comparison with other commercial rechargeable batteries, Li-ion batteries are characterized by higher specific energy, higher energy density, higher energy efficiency, a longer cycle life, and a longer calendar life. Also noteworthy is a dramatic improvement in lithium-ion battery properties after their market introduction in 1991: over the following 30 years, their volumetric energy density increased threefold while their cost dropped tenfold.
The vanadium redox battery (VRB), also known as the vanadium flow battery (VFB) or vanadium redox flow battery (VRFB), is a type of rechargeable flow battery. It employs vanadium ions as charge carriers. The battery uses vanadium's ability to exist in a solution in four different oxidation states to make a battery with a single electroactive element instead of two. For several reasons, including their relative bulkiness, vanadium batteries are typically used for grid energy storage, i.e., attached to power plants/electrical grids.
A flow battery, or redox flow battery, is a type of electrochemical cell where chemical energy is provided by two chemical components dissolved in liquids that are pumped through the system on separate sides of a membrane. Ion transfer inside the cell occurs across the membrane while the liquids circulate in their respective spaces.
Nanobatteries are fabricated batteries employing technology at the nanoscale, particles that measure less than 100 nanometers or 10−7 meters. These batteries may be nano in size or may use nanotechnology in a macro scale battery. Nanoscale batteries can be combined to function as a macrobattery such as within a nanopore battery.
Lithium cobalt oxide, sometimes called lithium cobaltate or lithium cobaltite, is a chemical compound with formula LiCoO
2. The cobalt atoms are formally in the +3 oxidation state, hence the IUPAC name lithium cobalt(III) oxide.
The lithium–air battery (Li–air) is a metal–air electrochemical cell or battery chemistry that uses oxidation of lithium at the anode and reduction of oxygen at the cathode to induce a current flow.
A metal–air electrochemical cell is an electrochemical cell that uses an anode made from pure metal and an external cathode of ambient air, typically with an aqueous or aprotic electrolyte.
Capacitive deionization (CDI) is a technology to deionize water by applying an electrical potential difference over two electrodes, which are often made of porous carbon. In other words, CDI is an electro-sorption method using a combination of a sorption media and an electrical field to separate ions and charged particles. Anions, ions with a negative charge, are removed from the water and are stored in the positively polarized electrode. Likewise, cations are stored in the cathode, which is the negatively polarized electrode.
A lithium-ion flow battery is a flow battery that uses a form of lightweight lithium as its charge carrier. The flow battery stores energy separately from its system for discharging. The amount of energy it can store is determined by tank size; its power density is determined by the size of the reaction chamber.
Pseudocapacitance is the electrochemical storage of electricity in an electrochemical capacitor that occurs due to faradaic charge transfer originating from a very fast sequence of reversible faradaic redox, electrosorption or intercalation processes on the surface of suitable electrodes. Pseudocapacitance is accompanied by an electron charge-transfer between electrolyte and electrode coming from a de-solvated and adsorbed ion. One electron per charge unit is involved. The adsorbed ion has no chemical reaction with the atoms of the electrode since only a charge-transfer takes place. Supercapacitors that rely primarily on pseudocapacitance are sometimes called pseudocapacitors.
Research in lithium-ion batteries has produced many proposed refinements of lithium-ion batteries. Areas of research interest have focused on improving energy density, safety, rate capability, cycle durability, flexibility, and reducing cost.
Lithium hybrid organic batteries are an energy storage device that combines lithium with an organic polymer. For example, polyaniline vanadium (V) oxide (PAni/V2O5) can be incorporated into the nitroxide-polymer lithium iron phosphate battery, PTMA/LiFePO4. Together, they improve the lithium ion intercalation capacity, cycle life, electrochemical performances, and conductivity of batteries.
A solid dispersion redox flow battery is a type of redox flow battery using dispersed solid active materials as the energy storage media. The solid suspensions are stored in energy storage tanks and pumped through electrochemical cells while charging or discharging. In comparison with a conventional redox flow battery where active species are dissolved in aqueous or organic electrolyte, the active materials in a solid dispersion redox flow battery maintain the solid form and are suspended in the electrolyte. Further development expanded the applicable active materials. The solid active materials, especially with active materials from lithium-ion battery, can help the suspensions achieve much higher energy densities than conventional redox flow batteries. This concept is similar to semi-solid flow batteries in which slurries of active materials accompanied by conductive carbon additives to facilitate electrons conducting are stored in energy storage tanks and pumped through the electrochemical reaction cells. Based upon this technique, an analytical method was developed to measure the electrochemical performance of lithium-ion battery active materials, named dispersed particle resistance (DPR).
Dispersed particle resistance (DPR) is a measured parameter to characterize battery active materials. It is seen as an indicator of lithium-ion battery active material rate capability. It is the slope of voltage-current linear fit for active material samples in suspensions. It can be obtained by applying different voltages on a suspension and measuring the currents, after which the data points are plotted. The slope of the plot is referred to as dispersed particle resistance. It can also be done in the opposite way where different currents are applied and voltages are measured. The key advantage of this dispersed particle resistance technique is fast and accurate comparing with the conventional characterization method for which batteries need to be fabricated and tested for a long time.
George William Crabtree was an American physicist known for his highly cited research on superconducting materials and, since 2012, for his directorship of the Joint Center for Energy Storage Research (JCESR) at Argonne National Laboratory.
Calcium (ion) batteries are energy storage and delivery technologies (i.e., electro–chemical energy storage) that employ calcium ions (cations), Ca2+, as the active charge carrier. Calcium (ion) batteries remain an active area of research, with studies and work persisting in the discovery and development of electrodes and electrolytes that enable stable, long-term battery operation. Calcium batteries are rapidly emerging as a recognized alternative to Li-ion technology due to their similar performance, significantly greater abundance, and lower cost.
The piezoelectrochemical transducer effect (PECT) is a coupling between the electrochemical potential and the mechanical strain in ion-insertion-based electrode materials. It is similar to the piezoelectric effect – with both exhibiting a voltage-strain coupling - although the PECT effect relies on movement of ions within a material microstructure, rather than charge accumulation from the polarization of electric dipole moments.
The Iron Redox Flow Battery (IRFB), also known as Iron Salt Battery (ISB), stores and releases energy through the electrochemical reaction of iron salt. This type of battery belongs to the class of redox-flow batteries (RFB), which are alternative solutions to Lithium-Ion Batteries (LIB) for stationary applications. The IRFB can achieve up to 70% round trip energy efficiency. In comparison, other long duration storage technologies such as pumped hydro energy storage provide around 80% round trip energy efficiency.