Battery chemistries

LMO blend (AESC, early Nissan LEAF)

The catalogue’s wording: “LMO with LiNiO₂ cathode, graphite anode (AESC)”, on the two 24 kWh LEAF packs.

What it is made of

A cathode of lithium manganese oxide (manganese “spinel”) blended with some lithium nickel oxide, and a graphite anode. Cheap, plentiful metals; little or no cobalt.

Energy density

Low to moderate by today’s standards, roughly comparable to LFP and well below modern nickel-rich NMC. These packs are large and heavy for the energy they hold.

Lifespan / cycle life

The shortest of the families here. Manganese tends to dissolve slowly from the cathode, especially when warm, so capacity fades faster with both use and time. Any surviving 2011–2016 pack has already lost a good share of its original capacity.

Safety / thermal runaway

Fairly good. Manganese spinel is more stable than nickel-rich or cobalt-rich cathodes, so runaway needs a higher temperature. It is still a flammable lithium-ion cell and still needs proper protection.

Cost

Low to make. Used, these are usually the cheapest packs per kWh, because they are old and well worn.

Thermal behaviour and cooling

Heat is the main enemy. The early LEAF pack has passive cooling only (no fan or liquid loop), and these packs became known for losing capacity quickly in hot climates.

As a second-hand house store

Workable for a small, cheap store if you accept limited remaining life. Keep the pack somewhere cool and shaded; a hot loft or a sunny garage wall will speed up wear. Calendar ageing is significant even when idle, more so at high charge, so don’t leave it sitting full. Use a cautious window (for example about 20–80% of what remains) and expect useful capacity to keep falling year on year. Check every module for weak cells before buying; worn packs often have one or two modules dragging the rest down.

LFP (lithium iron phosphate, LiFePO₄)

On the Tesla Model 3 RWD packs (CATL prismatic) and the BYD Blade packs in the Atto 3, Dolphin and Seal.

What it is made of

A cathode of lithium iron phosphate and a graphite anode. Iron and phosphate are cheap and common; there is no cobalt and no nickel. BYD’s Blade is a long, thin prismatic LFP cell built straight into the pack.

Energy density

The lowest of the mainstream EV families, though designs such as the Blade close the gap at pack level. Typical new cells: roughly 120–180 Wh/kg, against roughly 200–270 Wh/kg for nickel-rich NMC. For a fixed house store, weight and size matter much less than in a car.

Lifespan / cycle life

The longest. Typical published figures run to several thousand full cycles before falling to 80% capacity, often two to three times typical NMC. It also copes better with being held at a high state of charge.

Safety / thermal runaway

The safest family here. The phosphate cathode holds on to its oxygen, so runaway starts at a higher temperature and is less violent, with less heat released. Not risk-free: cells can still vent flammable gas if abused or short-circuited.

Cost

The cheapest family to make per kWh new, thanks to iron and the absence of cobalt and nickel. Used LFP EV packs are newer (2021 onwards) and less common, so used prices are not always lower than for older NMC.

Thermal behaviour and cooling

Tolerates heat better than nickel-rich cells. Weak in the cold: charging below about 0 °C can plate lithium on the anode and damage the cell, so most systems block or heat before charging in frost. The Tesla packs use a liquid base plate; the BYD packs use refrigerant direct cooling and heating.

As a second-hand house store

The best fit for daily solar cycling. It can use a wide window (often about 10–95%) without much extra wear, and calendar ageing is gentle. Two things to plan for: the voltage curve is very flat, so state-of-charge readings drift unless the system is fully charged every so often to recalibrate; and an unheated outbuilding in winter needs low-temperature charge protection, because the car’s pack heater won’t be working. No cobalt means lower fire severity and fewer sourcing concerns.

NMC / NCM (nickel manganese cobalt)

The largest named group in the catalogue. The ratio sets most of the trade-offs, so the subtypes are covered together below.

Subtypes in the catalogue

• NMC111: BMW i3 60 Ah. Lowest nickel, most cobalt; steadiest of the group, lowest energy.
• NMC622 / NCM622: BMW i3 120 Ah; Kia Niro EV. Middle of the range.
• NMC712 / NCM712: Porsche Taycan; Volkswagen ID.3 (LG pouch line).
• NMC811: BMW i4, BMW iX3, Mercedes-Benz EQS, Nissan Ariya. Highest nickel, least cobalt; most energy, most sensitive to heat. The 2026 UK LEAF card says “NMC” without a ratio.
• NCM, ratio not stated: Ford F-150 Lightning standard and extended range.

What it is made of

A layered cathode of nickel, manganese and cobalt oxides, with a graphite anode. Nickel brings energy, manganese brings stability, cobalt holds the structure together.

Energy density

Moderate (NMC111) to high (NMC811). Typical new cells: roughly 150–220 Wh/kg for older low-nickel cells, and up to about 250–270 Wh/kg for modern nickel-rich cells.

Lifespan / cycle life

Middling. Typical figures are in the region of 1,000–2,000 full cycles to 80%, depending heavily on depth of discharge and temperature. Lower-nickel types such as 111 and 622 usually age more gently than 811.

Safety / thermal runaway

Moderate risk, rising with nickel content. The cathode can release oxygen when overheated, so runaway starts at a lower temperature than LFP and burns hotter. NMC811 is the most sensitive here.

Cost

Higher than LFP to make, because of nickel and cobalt. Moving from 111 to 811 cuts cobalt but not total cost much. Used NMC packs are the most common on the market, which helps used prices.

Thermal behaviour and cooling

Ages faster when hot and when held at high charge. That is why these packs mostly have active cooling in the car: refrigerant on the i3, liquid plates on the i4, iX3, EQS, Taycan, ID.3, Niro and Ariya.

As a second-hand house store

A good store if kept cool and run in a narrower window, for example about 20–80% or 10–90%, avoiding long spells at full charge. Calendar ageing is noticeably faster at high charge and warm temperatures, so a charge-to-full-every-day, hold-all-afternoon pattern in a warm garage wears these faster than LFP. Away from the car, the cooling loop isn’t connected; at gentle house rates (a few kW from a large pack) heat build-up is small, but ambient temperature still matters, so pick a cool, ventilated spot. The cobalt and nickel mean higher fire energy than LFP if something goes wrong: fit the pack away from living space and escape routes, with proper fusing and a working battery management system (BMS).

NCA (nickel cobalt aluminium)

On the Tesla Model 3 2017 Long Range pack, with Panasonic 2170 cylindrical cells.

What it is made of

A nickel-rich cathode with a little cobalt and aluminium, and a graphite anode (often with some silicon). Thousands of small cylindrical cells make up the pack.

Energy density

High, similar to nickel-rich NMC. Typical new cells: roughly 200–260 Wh/kg.

Lifespan / cycle life

Moderate. Holds up well with shallow cycling, but wears faster with deep cycles and long periods at high charge.

Safety / thermal runaway

Among the most heat-sensitive families here: runaway can begin at a lower temperature than NMC and is energetic. The pack relies on cell fusing, spacing and active cooling to stop one failing cell setting off its neighbours.

Cost

Moderate to high to make. Used Tesla modules are fairly easy to find.

Thermal behaviour and cooling

Needs good temperature control; in the car, a liquid loop runs between the cells.

As a second-hand house store

Usable, but the least forgiving here. Run a conservative window (about 20–80%), keep it cool, and never leave it at full charge for long; calendar ageing at high charge is a known weak spot. Tesla modules run at higher voltage than many home inverters expect, so check the match before buying. Given the fire behaviour, install outside living space with good protection.

Lithium-ion, cathode not confirmed

Many cards name only “lithium-ion”, a cell maker and format, or “nickel-rich lithium-ion”, and 14 cards leave the chemistry blank. Examples: the LG Chem pouch packs (LEAF 30 kWh, Renault Zoe), the AESC LEAF 40 and 62 kWh, the Chevrolet Bolt EV (“nickel-rich lithium-ion (LG)”), the BMW i3 94 Ah, Samsung 50G 21700 cells in the Rivian R1T, and CATL or Samsung prismatic cells with no subtype.

What we know

These are lithium-ion with, almost certainly, a graphite anode. The source does not name the cathode, so this catalogue does not either. “Nickel-rich” suggests an NMC- or NCA-type cathode, but not which ratio.

What not to assume

Don’t read a chemistry off the brand or the year. The same maker, and sometimes the same car model, has used different chemistries from one cell supplier or market to the next (the ID.3 and XC40 sources both list more than one supplier).

How to find out

Look for the cell or module part number on the label and check it against the maker’s datasheet or a published teardown. Ask the seller for photos of the labels. The cell’s voltage limits on the datasheet or BMS also give strong clues: LFP cells sit around 3.2 V nominal (about 3.6 V full), while NMC and NCA cells sit around 3.6–3.7 V nominal (about 4.2 V full).

As a second-hand house store

Until the cathode is known, treat the pack as nickel-based (NMC/NCA): conservative charge window, cool location, fire separation from the house. Upgrade those assumptions only if the datasheet confirms LFP.

LCO (lithium cobalt oxide): not in the catalogue

No pack in the 56-pack catalogue lists LCO, and none of these traction packs is understood to use it.

What it is

A cathode made almost entirely of cobalt oxide, with a graphite anode. It is the classic chemistry in phones, laptops, tablets and cameras.

Why EV packs don’t use it

Cost and cobalt: cobalt is the most expensive and supply-sensitive metal here, and a car pack would need many kilograms of it. Thermal risk: LCO gives up oxygen at a relatively low temperature, so it is among the most prone to thermal runaway, which matters far more in a 60–100 kWh pack than in a phone. Life and power: it has a short cycle life and handles high charge and discharge currents poorly, both bad for a car that must last many years.

For a house store

Not relevant to these packs. Treat any “EV pack” listing claiming LCO with suspicion and ask for cell part numbers.