I thought Li-ion was Lituim Ion but Lifepo4 was Lithium Iron.
Both Lithium but one is Lion and the other Lifepo4...
The term ION, means an atom in an ionic state, i.e. it gained or lost some electrons.
Li is a lithium metal atom, and Li+, is a lithium ion. Fe is an
iron atom, while Fe2+ is an iron(II) ion, and Fe3+ is an iron(III) ion. H2 is a diatomic molecule in which the H has no nett charge (it did not lose or gain an electron) so it's an atom, but the H in HCl (pool acid) actually exists as the hydrogen ion (H+), together with the chloride ion (Cl-), in water. [I dunno how to sub/superscript here so the tokens not correctly subbed/supered].
So LiFePO4 is: a lithium(+) ion, and iron phospate.
NMC should be written LiNMC, and is: Li(+) ion, and nickel and manganese, and cobalt oxide.
Etc. for about 10 or more other Li ion battery types.
In each case the Li ion [Li+] is the main carrier of charge mostly, so people call all these batteries Li-ion. The life, power density, etc of each type chemistry differs distinctly though.
See the energy density graph at the botom of
https://batteryuniversity.com/article/bu-205-types-of-lithium-ion if you want to talk about energy density. LFP is far from the best, but very safe, and can handle many charge cycles.
Early on manufacturers did not differentiate, and Li ion I think meant mainly LTO (around since the 80s). Today, perhaps they want to hide fire hazards or something, or don't know any better, and still just call them Li ion. The charge curves and current handling of Li ion batteries in general is very different from lead acid (or gel, or calsium) batteries, so it's good to know it's Li ion in any case, even you don't know exactly what kind of Li ion.