Abstract: An electrical device including a surface which may be exposed to heat derived from operation of the electrical device such that the temperature of the surface increases during operation. The surface includes a temperature sensor including first and second electrodes separated by a layer of control material. The material properties and/or configuration of the control material are selected such that the electrical conductivity of the control material increases with increasing temperature so that electrical current is able to pass between the first and second electrodes once the temperature of any part of the control material has reached or exceeded a predetermined temperature. The temperature sensor extends over substantially the whole of the surface. A system including the electrical device and a method of controlling the electrical device is also disclosed.

Abstract: An electrical device including a surface which may be exposed to heat derived from operation of the electrical device such that the temperature of the surface increases during operation. The surface includes a temperature sensor including first and second electrodes separated by a layer of control material. The material properties and/or configuration of the control material are selected such that the electrical conductivity of the control material increases with increasing temperature so that electrical current is able to pass between the first and second electrodes once the temperature of any part of the control material has reached or exceeded a predetermined temperature. The temperature sensor extends over substantially the whole of the surface. A system including the electrical device and a method of controlling the electrical device is also disclosed.

Abstract: A battery cell including an electrode assembly contained within a housing. The electrode assembly shrinks and/or swells depending on a charge/discharge cycle of the cell. A swelling compensation member configured to shrink upon swelling of the electrode assembly, and expand upon on shrinking of the electrode assembly is in continuous contact with the electrode assembly and an innermost surface of the housing. A first portion of the innermost surface of the housing is in contact with the swelling compensation member, and a second portion is free from contact with the swelling compensation member. The battery cell includes a cooling member in thermal contact with the outermost surface of the housing. Part of the outermost surface of the housing in contact with the cooling member corresponds to a part of the innermost surface of the housing which is free from contact with the swelling compensation member.