A123 Systems LLC

University of Michigan

Gregory B Less

Susan J Babinec

Angela Knapp

Gilbert N Riley, Jr

Anna G Stefanopoulou

Jason Benjamin Siegel

Sravan Pannala

Mingxuan Zhang

Dave Vieau

Ting Cai

An electrical device comprises a battery cell; a pressure sensor for measuring swelling forces of the battery cell, optionally with voltage, temperature and current sensors, and a battery management system including a controller. The controller executes a program to: (i) determine a reference swelling force corresponding to a reference electrical signal received from the pressure sensor at an earlier reference time, (ii) determine a second swelling force corresponding to a second electrical signal received from the pressure sensor at a later second time, and (iii) determine whether a risk of internal short circuit of the battery cell exists by comparing a reference level of the reference electrical signal and a signal representative of the second electrical signal. When the signal representative of the second electrical signal exceeds the reference level of the reference electrical signal by a threshold amount, a risk of internal short circuit of the cell exists.

Detection of an internal short circuit in a battery

An electrode/separator assembly for use in an electrochemical cell includes a current collector; a porous composite electrode layer adhered to the current collector, said electrode layer comprising at least electroactive particles and a binder; and a porous composite separator layer comprising inorganic particles substantially uniformly distributed in a polymer matrix to form nanopores and having a pore volume fraction of at least 25%, wherein the separator layer is secured to the electrode layer by a solvent weld at the interface between the two layers, said weld comprising a mixture of the binder and the polymer. Methods of making and using the assembly are also described.

Separator for electrochemical cell and method for its manufacture

An electrochemical cell, such as Li-Ion, having (a) a positive electrode; (b) a negative electrode, (c) a porous inorganic/organic composite layer interposed between the positive electrode and the negative electrode, and (d) an electrolyte comprising a lithium salt and a non-aqueous solvent. The composite layer includes inorganic nanoparticles and a binder to form a nanocomposite separator (NCS). In addition to the composite layer, the electrochemical cell includes a porous separator.

Batteries having inorganic/organic porous films

Electrodes with a multilayer or monolayer composite separator are described. The multilayer composite separator comprises multiple individual composite separator layers. Each individual composite separator layer comprises inorganic particulate material(s) and organic polymer(s) with different inorganic particulate material/polymer weight ratios. The multilayer composite separator layer is constructed in a way such that the composite separator layer adjacent to the electrode active material contains a higher weight percentage of the inorganic particulate material and lower weight percentage of the organic polymer than the composite separator layer outermost from the electrode current collector. Laminated cells comprising a positive electrode, a negative electrode, a laminated multilayer or monolayer composite separator layer are described, wherein at least one of the electrodes has a multilayer or monolayer composite separator disposed onto the surface of the electrode. Methods of making such laminated cells are also described.

Laminated battery cell comprising multilayer composite separator and methods for creating the same

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Ypsilanti, MI, United States of America

Gregory B Less