Where carbon shows up in a battery cell
Casing & Thermal
Carbon heat-spreaders and thermal interface materials move heat out of the cells, and graphene thermal-switch layers can throttle heat flow to slow a runaway. Carbon-fibre composite enclosures add a light, stiff, protective shell.
Anode
Graphite is the active anode material in more than 90 percent of lithium-ion batteries, holding lithium ions during charge. Silicon-graphite blends are now being added to raise capacity.
Current Collector
A thin carbon coating on the aluminium and copper current-collector foils lowers contact resistance, improves adhesion of the electrode, and protects the metal from corrosion, raising power and cycle life.
BMS
The battery management system estimates state of charge and state of health from current, voltage and temperature. Carbon-based sensors give it finer signals, strain, internal temperature and vented gas, for earlier warning of faults.
Cathode Additive
Cathode materials conduct electricity poorly. A few percent of conductive carbon, carbon black today and increasingly carbon nanotubes or graphene, forms a percolation network that carries electrons and lets the cell charge and discharge faster, for about 1 to 2 percent of cell cost.
Sensors
Graphene and carbon-nanotube sensors embedded on or in the cell measure temperature, pressure, strain and escaping gases, detecting the first signs of thermal runaway earlier than voltage and current alone.
The numbers behind carbon in batteries
These figures are indicative estimates that vary by scope.
Why a battery is a carbon device
A lithium-ion cell is, in large part, a carbon device. The anode is graphite, which holds lithium ions as the cell charges and still accounts for more than nine in ten anodes in production. On the other side, the cathode active material conducts electricity poorly, so manufacturers blend in a few percent of conductive carbon to build a network that moves electrons through the electrode and allows fast charge and discharge.
Carbon then shows up in the supporting cast. Thin carbon coatings on the metal current collectors cut resistance and guard against corrosion. Carbon heat-spreaders, thermal interface materials and graphene thermal-switch layers manage and contain heat across the pack, and carbon-based sensors watch for the strain, temperature and gas signatures that precede a thermal runaway, feeding earlier warnings to the battery management system.
As electric vehicles and grid storage scale, every one of these roles scales with them. ACC tracks the producers, the science and the market behind battery-grade carbons so members can see where adoption is established, where it is still emerging, and who is supplying it.
Key carbons used in batteries
Drawn from materials ACC has linked to battery coverage and producers. Each links to its full material profile.
