The Periodic Table of the EV
An illustrated first-principles reference on why an electric vehicle is built from the elements it is built from — why lithium won, why every other element is where it is, and the physics underneath. Twenty-nine drawn plates across thirteen chapters. Companion to the Battery 101 series.
13 chapters published
How to read this series
Each chapter starts in plain language and ends with real equations, worked examples and questions to test yourself. No prior background is assumed — but nothing is hand-waved either. Chapters build on each other, so reading in order pays off, though each is written to stand alone.
Part 1
The Periodic Logic
The handful of periodic properties that decide everything downstream — effective nuclear charge, ionic radius, charge density and standard electrode potential — and then the seven independent reasons lithium won, set against an honest account of why sodium, magnesium and aluminium have not.
The Periodic Properties That Govern Everything
Effective nuclear charge, ionic radius, charge density, electrode potential and the two equations that turn a position in the periodic table into a number on a datasheet.
Almost every property of a battery traces back to five periodic quantities and two equations. This chapter defines each one precisely — effective nuclear charge and why it is the master variable, atomic versus ionic radius, charge density and polarising power, ionisation energy and electronegativity, and standard electrode potential — then shows with a Born–Haber cycle why lithium has the most negative potential of any element despite having the highest ionisation energy of the alkali metals, and derives the specific capacity formula that makes light elements win for free.
Why Lithium — in Seven Arguments
Any one of these would be an advantage. Lithium has all seven at once, and no other element has more than three. Plus an honest account of where sodium, magnesium, aluminium and zinc genuinely compete.
Seven independent arguments for lithium — the most negative electrode potential of any element, the lightest metal, the only monovalent ion small enough to intercalate quickly, a self-limiting SEI, a wide practical electrolyte window, a stoichiometry that fits graphite, and workable metallurgy — each stated with the number behind it. Then the counter-arguments stated fairly, and a candidate-by-candidate account of why hydrogen, sodium, potassium, magnesium, calcium, aluminium, zinc and beryllium fail, including the two that genuinely compete in specific applications.
Part 2
The Cathode
Why every practical cathode redox centre is a d-block transition metal, what crystal field splitting has to do with voltage, the specific case for nickel, cobalt, manganese, iron and aluminium — and the phosphorus trick that made iron useful.
Why Cathodes Are Transition Metals
Variable oxidation state is a d-orbital property, crystal field splitting sets the voltage, and the oxygen 2p band sets a ceiling that no amount of engineering raises.
A cathode has five jobs, and one of them makes the d-block mandatory: it must accept and release electrons reversibly, thousands of times, at high potential. Main-group elements have fixed oxidation states because the next electron comes out of a filled shell. Transition metals have partially filled d orbitals whose successive ionisation energies rise gently. This chapter covers crystal field theory and where voltage actually comes from, high-spin versus low-spin and why it decides structural stability, and the band-structure argument that explains why nickel-rich cathodes are simultaneously higher capacity and less thermally stable — one trade-off, not two facts.
Nickel, Cobalt, Manganese, Iron and Aluminium
Nickel supplies electrons, cobalt supplies structure, manganese supplies cheapness with a Jahn–Teller liability, iron supplies abundance — and aluminium supplies nothing at all, which is the point.
The specific case for each cathode metal, and the specific defect that comes with it. Why nickel raises capacity and why Ni²⁺ at 69 pm sits so close to Li⁺ at 76 pm that it invades the lithium layer. Why cobalt’s low-spin rigidity makes it the structural glue nobody has fully replaced. Why manganese is cheap and stable as Mn⁴⁺ but ruinous as Mn³⁺, through the Jahn–Teller theorem and disproportionation. Why iron is ideal on every economic axis and still needs help to reach a useful voltage. And why an element contributing zero capacity earns its place in NCA.
Oxygen, Phosphorus and the Inductive Effect
LFP’s celebrated safety is not a property of iron. It is a property of the phosphorus–oxygen covalent bond — and so is the voltage that made LFP viable at all.
Why oxygen is the framework anion of essentially every practical cathode, and what changes when you substitute sulfur below it. Then the most elegant piece of periodic-table reasoning in battery materials: phosphorus is more electronegative than iron, so the covalent P–O bond withdraws electron density from oxygen, which withdraws less from iron, which makes the Fe–O bond more ionic and lifts the Fe²⁺/Fe³⁺ couple from about 3.0 V to 3.45 V. Phosphorus contributes no capacity and adds mass; it earns its place entirely through that inductive effect and through locking oxygen into a rigid tetrahedron. Both of LFP’s famous weaknesses come from the same structure.
Part 3
The Anode and the Electrolyte
Why carbon and essentially only carbon hosts lithium cheaply and reversibly, what silicon changes and what it costs, and how fluorine and a mixture of carbonate solvents produce a liquid that conducts ions across a 3.5 volt window without decomposing.
Why the Anode Is Carbon
sp² hybridisation produces a layered, conductive, van-der-Waals-bonded host that lithium enters cheaply and reversibly. Silicon stores ten times as much and expands 280 per cent doing it.
Graphite’s structure follows directly from sp² hybridisation: three σ bonds in a plane, a delocalised π system that makes the anode conduct without additives, and only van der Waals forces between sheets — which is the intercalation gallery. This chapter derives LiC₆ at 372 mAh/g, explains staging and the stepped voltage profile it produces, and then gives the complete first-principles account of the cold-charging prohibition as a 100 millivolt margin consumed by kinetics. Silicon, LTO and hard carbon follow, each as a deliberate trade of one property for another.
Fluorine, Solvents and the Electrolyte
The most electronegative element appears in four places in a cell, each for a different consequence of the same property — and it generates hydrofluoric acid as a parting gift.
Fluorine appears in the salt anion, in the electrolyte’s oxidative stability, in the SEI and in the binder, and every one of those roles traces to χ = 3.98. This chapter explains weakly coordinating anions and why a simple chloride would give a poorly conducting solution, then works through the reason a solvent must be a mixture: high dielectric constant to dissociate the salt and low viscosity to move the ions are contradictory demands. Donor number, transference number and desolvation follow, along with the HF generation pathway that dictates dry-room manufacturing below 1 per cent relative humidity.
Part 4
Structure and Transport
The parts of a cell that are physics rather than chemistry: why copper and aluminium foils cannot swap places, and how porosity, tortuosity and the square of the diffusion length decide whether a thermodynamically excellent material is a product or a laboratory curiosity.
Copper and Aluminium: Why the Foils Cannot Swap
Routinely explained as a cost decision. It is not — it is standard electrode potential, and getting it wrong dissolves one foil and destroys the other.
Aluminium on the cathode, copper on the anode, and the assignment is electrochemical rather than economic. Copper dissolves above +3.45 V vs Li/Li⁺, so it cannot survive at cathode potential. Aluminium is thermodynamically more reactive still but survives by kinetics, forming a passivating AlF₃ layer that depends on the salt — which is why switching from LiPF₆ to LiTFSI is never simple. Aluminium alloys with lithium below 0.3 V so it cannot sit at the anode. The chapter closes with the reason over-discharge is permanently destructive and why thin and composite collectors are being pursued.
Porosity, Tortuosity and the Physics That Isn’t Chemistry
Everything else in this series concerns what the atoms do. This concerns whether the ions can get there in time — which is where a good material becomes a bad electrode.
Porosity sets the trade between energy and power, and calendering is the single process parameter that decides it — an energy cell and a power cell can share identical chemistry. Tortuosity then imposes a hidden penalty: the Bruggeman relation puts effective ionic conductivity inside a 30 per cent porous electrode at about one-sixth of the free electrolyte value, so every rate calculation that ignores it is wrong by a factor of six. The chapter closes on the L²/D diffusion time constant, worked through for LFP to show why commercial LFP is nano-sized — the difference between seven hours and 2.5 seconds.
Part 5
Beyond the Cell
The elements an EV needs outside the battery — magnet rare earths, copper windings, wide-bandgap semiconductors — how spectroscopy and diffraction let us measure any of this, and why crustal abundance is a long-run price forecast.
The Elements Outside the Cell
Buried 4f orbitals make the magnets, a filled 3d shell makes the windings, and a wide bandgap is the reason 800 V architectures arrived with silicon carbide and not before.
Why deeply buried 4f electrons give neodymium magnets their enormous magnetocrystalline anisotropy and therefore their coercivity, why dysprosium is added despite being one of the scarcest elements in the crust, and what the rare-earth-free alternatives cost. Then copper, whose single mobile 4s electron above a filled 3d shell gives it the second-highest conductivity of any element and puts 60 to 85 kg into every EV. Then the bandgap argument for silicon carbide, worked through to show why 800 V systems needed it. Platinum, iridium and the structural metals close the chapter.
Wavelength: How We Actually See Any of This
Every claim in this series is measurable, and almost every measurement is a wavelength measurement. The lithium flame test crimson is you observing the 2s valence electron the industry depends on.
Atomic emission gives each element an unforgeable fingerprint, and the wavelengths themselves report the valence energy-level spacing that Part 1 argued from. This chapter covers ICP, LIBS and AAS; Bragg’s law and what XRD actually tells you, including the (003)/(104) ratio that quantifies cation mixing; why neutrons rather than X-rays are needed to locate lithium at all; Raman and the I_D/I_G ratio that screens anode material; XPS for oxidation state in the top ten nanometres; and EIS, where frequency substitutes for wavelength to separate why a cell’s resistance grew.
Abundance, Geochemistry and Why Cost Is a Periodic Property
Elemental abundance was set by nucleosynthesis and then sorted by Earth’s differentiation. Read down the abundance column and the trajectory of the battery industry is legible in advance.
Why iron is abundant and everything heavier is rare, and why lithium, beryllium and boron are anomalously scarce for their atomic number — destroyed in stellar interiors rather than made there. Then the Goldschmidt classification, which explains the industry’s supply structure directly: lithium is lithophile and reachable but localised, nickel and cobalt are siderophile so most of Earth’s inventory sank into the core, and cobalt is almost always a byproduct of copper or nickel mining, a geochemical constraint on supply elasticity that investment does not fix quickly.
Part 6
Reference
Every term defined in one place, with the element data table the rest of the series argues from.
More chapters are being written. A companion reference to Battery 101, illustrated with twenty-nine drawn plates. Where that series covers what a cell does and how to specify one, this one covers why the atoms behave that way.