3m Innovative Properties Company

Jeffery R Dahn

Donald J McClure

Larry J Krause

Ou Mao

Robert L Turner

Mary M Buckett

Timothy D Hatchard

Eddie R Buiel

Dean D MacNeil

Characterizing electrochemical cell components and a response of an electrochemical cell to a specified operating condition involves preparing a sample of an electrode material in contact with an electrolyte. Self-heating, power-temperature or power-time data is obtained for the sample using a calorimetry technique, such as by use of an accelerating rate calorimetry technique or a differential scanning calorimetry technique. A power function is developed for the sample using the self-heating, power-temperature or power-time data. The power function is representative of thermal power per unit mass of the sample as a function of temperature and amount of reactant remaining from a reaction of the sample electrode material and electrolyte. A first power function is developed that characterizes a reaction between the cathode material and the electrolyte in terms of thermal power per unit mass of a cathode sample material, and a second power function is developed that characterizes a reaction between the anode material and the electrolyte in terms of thermal power per unit mass of the anode sample material. An electrode material sample from which a power function is developed is prepared using less than about 100 grams of the electrode material, such as between about 1 and 10 grams, but may be as little as between about 1 milligram and 1 gram. A computer system and computer-readable medium are provided to electronically design and test cells of arbitrary size and shape using power functions developed for individual electrode/electrolyte combinations.

Method and apparatus for characterizing high-energy electrochemical cells using power functions obtained from calorimetry

An electrode composition that includes (a) an electrochemically active metal element which, prior to cycling, is in the form of an intermetallic compound or an elemental metal and (b) a non-electrochemically active metal element. The electrode compositions have high initial capacities that are retained even after repeated cycling. The electrode compositions also exhibit high coulombic efficiencies.

Electrode compositions with high coulombic efficiencies

An electrode for a lithium battery that includes (a) an electrochemically active metal element which, prior to cycling, is in the form of an intermetallic compound or an elemental metal and (b) a non-electrochemically active metal element. The electrode have high initial capacities that are retained even after repeated cycling. The electrode also exhibit high coulombic efficiencies.

Electrode for a lithium battery

A method for making a carbonaceous material suitable for use as an electrode composition that includes contacting pyrolyzed organic material with hydrocarbon gas for a period and at a temperature sufficient to produce a carbonaceous material characterized such that when the carbonaceous material is incorporated into an electrode composition of a lithium-ion cell, the cell exhibits a reversible capacity of at least about 400 mAH/g of carbonaceous material and an irreversible capacity no greater than about 140 mAH/g of carbonaceous material, the capacities being measured up to the point of plating of metallic lithium on the surface of the carbonaceous material.

Growing community of inventors

Hubley, Canada

Jeffery R Dahn