A nanofluid contact potential difference cell comprises a cathode with a lower work function and an anode with a higher work function separated by a nanometer-scale spaced inter-electrode gap containing a nanofluid with intermediate work function nanoparticle clusters. The cathode comprises a refractory layer and a thin film of electrosprayed dipole nanoparticle clusters partially covering a surface of the refractory layer. A thermal power source, placed in good thermal contact with the cathode, drives an electrical current through an electrical circuit connecting the cathode and anode with an external electrical load in between. A switch is configured to intermittently connect the anode and the cathode to maintain non-equilibrium between a first current from the cathode to the anode and a second current from the anode to the cathode.

An electrochemically active material includes a sodium metal oxide of formula (I): Na.sub.xM.sub.yTi.sub.zO.sub.2 (I) In formula (I), 0.2<x<1, M comprises one or more first row transitions metals, 0.1<y<0.9, 0.1<z<0.9; and x+3y+4z=4.

Provided is a method for producing a negative electrode for an electric storage device, the method comprising the steps of preparing a negative electrode composition comprising a negative electrode active material that reversibly carries a sodium ion, metal sodium, and a liquid dispersion medium for dispersing them; allowing a negative electrode current collector to hold the negative electrode composition; evaporating at least part of the liquid dispersion medium from the negative electrode composition held by the negative electrode current collector, thereby giving a negative electrode precursor comprising the negative electrode active material, the metal sodium, and the negative electrode current collector; and bringing the negative electrode precursor into contact with an electrolyte having sodium ion conductivity, thereby doping the negative electrode active material with sodium eluted from the metal sodium.

Provided are a carbon electrode particularly suitable to be used as a negative electrode of an energy storing apparatus and the like and a method for manufacturing the same by forming the carbon electrode by heat-treating a natural carbon material such as a natural fiber sheet including a natural fiber or cellulose sheet including a natural cellulose fiber which is a natural material other than a petroleum-based material or a petroleum-based synthetic material to reduce manufacturing cost, shorten a manufacturing process, minimize discharge of a hazardous substance, and uniformly maintain storage capacitance even in repeated charging and discharging when being applied to the energy storing apparatus. The carbon electrode includes any one of an alkaline metal particle and an alkaline earth metal particle having an average particle size of less than 100 nm which is formed on a surface in a process of carbonizing a natural carbon material.

A rechargeable electrochemical battery cell with a housing, a positive electrode, a negative electrode and an electrolyte which contains SO.sub.2 and a conducting salt of the active metal of the cell, whereby at least one of the electrodes contains a binder chosen from the group: Binder A, which consists of a polymer, which is made of monomeric structural units of a conjugated carboxylic acid or of the alkali salt, earth alkali salt or ammonium salt of this conjugated carboxylic acid or a combination thereof or binder B which consists of a polymer based on monomeric styrene structural units or butadiene structural units or a mixture of binder A and B.

Electrode materials comprising an electrochemically active material, wherein said electrochemically active material comprises a layered potassium metal oxide. The layered potassium metal oxide may be of formula K.sub.xMO.sub.2. The invention also relates to electrodes, electrochemical cells and batteries comprising said electrode material. For example, said battery may be a lithium or lithium-ion battery, a sodium or sodium-ion battery, or a potassium or potassium-ion battery.

A process for treating an electrochemical cell is presented. The process includes charging the electrochemical cell in a discharged state to at least 20 percent state-of-charge of an accessible capacity of the electrochemical cell at a first temperature to attain the electrochemical cell in a partial state-of-charge or a full state-of-charge and holding the electrochemical cell in the corresponding partial state-of-charge or full state-of-charge at a second temperature. The first temperature and the second temperature are higher than an operating temperature of the electrochemical cell.

Provided herein are energy storage devices. In some cases, the energy storage devices are capable of being transported on a vehicle and storing a large amount of energy. An energy storage device is provided comprising at least one liquid metal electrode, an energy storage capacity of at least about 1 MWh and a response time less than or equal to about 100 milliseconds (ms).

A positive electrode for a sodium ion battery is provided. The positive electrode includes a sodium metal vanadium fluorophosphate having a formula according to Formula I:

Na.sub.3V.sub.2-xM.sub.xO.sub.y(PO.sub.4).sub.2F.sub.3-y  I;

wherein 0<x≤1, 0≤y≤1, and M is one or more additional metals.

Presented are new, earth-abundant lithium superionic conductors, Li.sub.3Y(PS.sub.4).sub.2 and L1.sub.5PS.sub.4Cl.sub.2, that emerged from a comprehensive screening of the Li—P—S and Li—M—P—S chemical spaces. Both candidates are derived from the relatively unexplored quaternary silver thiophosphates. One key enabler of this discovery is the development of a first-of-its-kind high-throughput first principles screening approach that can exclude candidates unlikely to satisfy the stringent Li+ conductivity requirements using a minimum of computational resources. Both candidates are predicted to be synthesizable, and are electronically insulating. Systems and methods according to present principles enable new, all-solid-state rechargeable lithium-ion batteries.