the present invention relates to an oxyhalide electrochemical cell comprising an anode of a group ia metal and a cathode of a composite material prepared from a first electrochemically active carbonaceous material and a second electrochemically non - active carbonaceous material . the cathode material of the present invention provides increased discharge capacity compared to traditional lithium oxyhalide cells . in addition , the cathode material of the present invention is chemically stable which makes it particularly useful for applications that require increased rate capability in extreme environmental conditions such as those found in oil and gas exploration .