Electric Vehicles
Battery chemistry, without the marketing
Every chemistry trades energy density against cost, longevity, safety and materials. There is no chemistry that wins on all of them.
Lithium-ion is not one thing. The chemistry inside varies substantially, and the differences explain most of the confusing variation between vehicles.
How a cell works
Lithium ions move between two electrodes through an electrolyte. On discharge they leave the anode and enter the cathode, releasing energy; charging reverses it.
The anode in almost all commercial cells is graphite, sometimes with silicon added to increase capacity.
The cathode is where the chemistries differ, and where most of the cost and most of the performance characteristics live.
The main cathode families
NMC — nickel, manganese, cobalt.
High energy density, which means more range per kilogram and per litre. The mainstream chemistry for long-range vehicles.
Cobalt is expensive and carries well-documented supply chain and human rights concerns, particularly around artisanal mining. The industry response has been to raise nickel content and reduce cobalt, which improves energy density and cost and makes the cell more thermally sensitive.
NCA — nickel, cobalt, aluminium. Similar positioning to high-nickel NMC.
LFP — lithium iron phosphate.
Lower energy density, so a given range needs a larger, heavier pack.
In exchange: substantially cheaper, no cobalt or nickel, far longer cycle life, and considerably better thermal stability — the failure temperature is higher and the failure is less energetic.
LFP has taken a large and growing share of the market, particularly for standard-range vehicles and for stationary storage, where volume and mass matter little and cycle life matters enormously.
It also tolerates being charged to one hundred percent routinely, which NMC does not, and it has a flatter voltage curve that makes state-of-charge estimation harder — which is why LFP vehicles frequently ask you to charge to full periodically to recalibrate.
LMFP, adding manganese to LFP for higher voltage and energy density while keeping the cost and safety advantages. An active development area.
Sodium-ion, replacing lithium entirely with abundant sodium.
Lower energy density again, potentially much cheaper, better cold-weather performance, and no lithium supply exposure. Early commercial cells exist and stationary storage is the obvious first market.
Solid state, honestly
The chemistry most frequently announced and least frequently shipped.
Replacing the liquid electrolyte with a solid one would in principle allow a lithium metal anode, giving a substantial energy density increase, and would remove the flammable liquid.
The obstacles are real and specific: maintaining contact between solid surfaces as electrodes expand and contract through cycling; dendrite growth through the solid electrolyte; manufacturing at scale and yield; and cost.
Progress is genuine. Timelines announced over the past decade have consistently slipped, and a reasonable position is to treat any specific date with caution while accepting that the direction is real.
Pack-level design
Cell chemistry is only part of the story.
Cell format — cylindrical, prismatic or pouch — affects cooling, packaging efficiency and manufacturing.
Cell-to-pack designs eliminate the module layer, improving volumetric efficiency substantially. Structural packs go further, making the pack a load-bearing element of the vehicle.
These have delivered energy density gains at the vehicle level without any chemistry change, which is why comparing cell-level figures between manufacturers is misleading.
Thermal management determines charging speed, cold-weather behaviour and longevity. Liquid-cooled packs outperform air-cooled ones on all three.
Degradation, briefly
Two mechanisms, both worth knowing.
Calendar ageing happens with time, accelerated by high state of charge and high temperature. A pack sitting at full charge in a hot climate degrades even unused.
Cycle ageing happens with use, accelerated by deep discharge, high charge rates and temperature extremes.
Which produces the standard guidance: for NMC, keep daily charging around eighty percent, avoid leaving it very full or very empty for long periods, and prefer AC charging where convenient. For LFP, charge to full without concern.
The materials question
Lithium, nickel, cobalt, graphite and manganese all have concentrated supply chains and real extraction impacts.
The direction of travel — less cobalt, more LFP and sodium-ion, better recycling — reduces exposure, and none of it eliminates the fact that batteries are mined.
Recycling is improving and is currently limited by feedstock: there are not yet many end-of-life EV packs. That changes over the coming decade, and the recycling economics improve substantially with volume.
