An electric car battery is built from a mix of metals, minerals, and chemical compounds layered inside thousands of individual cells, all housed in a sealed pack that can weigh 400 kilograms or more. The core chemistry relies on lithium, but lithium is just one ingredient in a complex system that includes nickel, cobalt, graphite, copper, aluminum, liquid electrolyte, and a range of structural and cooling components.
The Cell: Where Energy Is Stored
Each battery pack contains hundreds or thousands of individual cells, and every cell has the same basic anatomy: a cathode (positive side), an anode (negative side), an electrolyte that carries charged particles between them, and a thin separator that keeps the two sides from touching. The specific materials in each layer determine how much energy the battery holds, how fast it charges, how long it lasts, and how much it costs.
Cathode Materials: The Biggest Variable
The cathode is the most chemically complex part of the battery, and its composition varies depending on the type of cell. Three cathode chemistries dominate the EV market right now.
NMC (nickel-manganese-cobalt) is the most common type, found in vehicles from the Nissan Leaf to the Mercedes-Benz EQS. In its original formulation, the cathode contains roughly equal parts nickel, manganese, and cobalt. Newer versions use a higher proportion of nickel to boost energy density while reducing the amount of cobalt, which is expensive and difficult to source ethically.
NCA (nickel-cobalt-aluminum) replaces the manganese with aluminum, which improves lifespan. This chemistry was used in older Tesla models like the Model S, Model X, and pre-facelift Model 3, though it has become less common.
LFP (lithium-iron-phosphate) skips nickel and cobalt entirely, using iron and phosphorus instead. That makes it significantly cheaper to manufacture. LFP is increasingly popular in entry-level and standard-range EVs because it’s more affordable, longer-lasting in terms of charge cycles, and more thermally stable. The tradeoff is lower energy density, meaning a heavier pack for the same range.
All three cathode types also contain lithium and oxygen as essential parts of their crystal structure, plus an aluminum foil layer that serves as the current collector on the cathode side.
Anode Materials: Mostly Graphite
The anode in nearly every EV battery is made primarily of graphite, a form of carbon. Graphite can be natural (mined) or synthetic (manufactured from petroleum coke), and most cells use one or a blend of both. The graphite is coated onto a thin copper foil, which acts as the current collector for the negative side of the cell.
Some newer cells mix small amounts of silicon into the graphite anode. Silicon can absorb far more lithium ions than graphite alone, which increases energy density. But silicon expands and contracts dramatically during charging, so manufacturers add it in limited ratios to balance performance with durability.
Electrolyte and Separator
The electrolyte is the liquid medium that allows lithium ions to shuttle between the cathode and anode during charging and discharging. In most EV batteries, it’s a lithium salt dissolved in organic solvents. The salt provides the lithium ions, and the solvents keep them mobile. This liquid is flammable, which is one reason battery safety engineering is so critical.
Sitting between the cathode and anode is a thin polymer separator, typically made of polyethylene or polypropylene. It’s porous enough to let lithium ions pass through but physically prevents the two electrodes from making direct contact, which would cause a short circuit.
How Much Metal Goes Into a Pack
For a typical 60 kWh battery pack (a common mid-range size), the raw material quantities are substantial. The pack uses roughly 29 kg of nickel, 20 kg of copper, 8 kg of cobalt, and 6 kg of lithium. Aluminum is present both in the cathode chemistry and in the structural casing and foils, adding significant weight as well. LFP packs swap out the nickel and cobalt for iron and phosphorus, shifting the mineral profile considerably.
Copper alone makes up about 10.8% of total pack weight, used in current collectors, wiring, and the busbars that carry high-voltage power between cells.
Beyond the Cells: Pack-Level Components
The cells themselves are only part of what’s inside an EV battery. A complete battery pack integrates several additional systems to keep everything running safely and efficiently.
Cells are grouped into modules, which are then wired together using busbars: solid metal conductors (usually copper or aluminum) that carry current between cells, modules, and the vehicle’s electrical system. These busbars are insulated with coatings or heat-shrink materials and operate at voltages ranging from 100 to 800 volts depending on the vehicle.
A battery management system (BMS) monitors every cell’s voltage, temperature, and state of charge in real time. It balances the cells to prevent any single one from overcharging or draining too far, which protects both performance and longevity. The BMS communicates through signal-level wiring throughout the pack.
The entire assembly sits inside a protective enclosure, typically made of aluminum or steel, designed to shield the cells from road debris, moisture, and impact forces in a crash.
Thermal Management
Lithium-ion cells perform best within a narrow temperature window, so nearly every modern EV battery includes an active cooling (and heating) system. The most common design uses cooling plates integrated into the pack, with a 50/50 mixture of ethylene glycol and water circulating through channels to absorb heat. This is the same type of coolant used in a conventional car’s radiator, repurposed to regulate battery temperature.
A thermal interface material sits between the cells and the cooling plate to improve heat transfer. The cooling plates themselves can be metallic or, in some designs, plastic composites. In cold weather, the same system can warm the cells before charging to prevent damage from low-temperature charging, which degrades the anode over time.
How It All Adds Up
When you look at what’s physically inside an EV battery, it’s a layered system. At the chemical level, you have lithium, nickel, cobalt, manganese, iron, phosphorus, graphite, silicon, aluminum, copper, and organic solvents, all arranged in precise layers within each cell. At the structural level, you have polymer separators, metal foils, plastic insulation, busbars, wiring harnesses, cooling plates, glycol coolant, and an armored outer casing. Coordinating all of it is a network of sensors and electronics that make up the battery management system. A single EV battery pack is, in effect, a carefully engineered chemical plant sealed into a slab under your car’s floor.