▎ 摘　　要

NOVELTY - The layer has pore walls containing pristine graphene material having less than 0. 01% by weight of non-carbon elements or non-pristine graphene material having 0.01% to 5% by weight of non-carbon elements. Cathode active material particle or coating is selected from metal fluoride or metal chloride, has size from 1 nm to 10 m, and is in an amount from 1% to 99.9% by weight based on total weight of combined graphene foam and cathode active material. Some of pores are lodged with the cathode active material particle or coating. The graphene foam is sufficiently elastic to accommodate volume expansion and shrinkage of the cathode active material particle or coating during a battery charge-discharge cycle to avoid expansion of a cathode layer. The non-carbon elements include an element selected from oxygen, fluorine, chlorine, bromine, iodine, nitrogen, hydrogen or boron. USE - Cathode or positive electrode layer for a lithium battery e.g. lithium-ion battery or lithium metal battery (all claimed), utilized in portable devices e.g. smart phones and electric vehicles. ADVANTAGE - The layer provides effective supporting material for metal fluoride and chloride so as to enable a high cathode active material utilization rate, high specific capacity at high and low charge/discharge rates, high rate capability, long cycle-life and improved heat dissipation generated during a battery operation. The layer provides a thermally conductive additive for dissipating heat generated from electrochemical operation of the lithium-ion battery, thus increasing reliability of the battery and decreasing a probability that the battery suffers from thermal runaway and rupture. The layer treats natural graphite due to weak van der Waals forces holding parallel graphene layers, so that a spacing between the graphene layers can be appreciably opened up to provide marked expansion in a c-axis direction, thus forming an expanded graphite structure in-which a laminar character of carbon layers is retained. The layer provides low electrical conductivity to provide high internal resistance and a necessity to add a large amount of conductive additives, thus effectively reducing a proportion of electrochemically active material in the cathode that has low capacity. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for the following: (1) a lithium battery (2) a process for producing a cathode layer. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of graphene foam-protected cathode active material.