They had historically, however, been unable to compete with NMC layered oxides in terms of energy density, and thus their impact within the rapidly growing EV sector was secondary. This paradigm has been broken in recent years due to impressive developments in cell and system design, whereby cell/automotive manufacturers (such as BYD) have taken advantage of the excellent safety characteristics of phosphate cathodes (high thermal runaway temperature) to adopt a "cell-to-pack" design strategy. With this approach, assembling large cells directly into a pack without the use of an intermediate module stage, the relative quantity of "inactive" components within the battery system are reduced, enabling greater levels of system-level energy density. Additionally, the lower risk of LFP cell rupture/explosion and propagation compared with NMC further reduces the need for inactive packaging. Thus the energy density gap between layered oxides and phosphate systems has narrowed significantly, which has given rise to a renaissance in phosphate usage over the last 5 years. Alongside these engineering developments is the emergence of new LMFP materials, in which some of the Fe in LFP is replaced with Mn, providing greater energy density through the higher oxidation potential of the Mn 2+/3+ redox couple. However, this advantage comes at a cost. Higher Mn content reduces electrode kinetics due to poor ionic and electronic conductivity associated with Jahn-Teller and polaron distortions. Additionally, cell lifetime can be shortened through Mn disproportionation and dissolution. Thus, there exists a balance between the potential energy density gains from higher Mn content, and the greater stability and fast charging capability offered by higher Fe content. LMFP has begun to be adopted in the commercial space, with manufacturers such as CATL and Gotion announcing LMFP (or LMFP-like) batteries. More recently, blends of LMFP and NMC have emerged as potential candidates to further bridge the energy density gap between olivines and layered oxides. Here a "best of both worlds" is hypothesised, whereby the material can benefit from the higher energy density of NMC while maintaining the good safety characteristics and cell-to-pack efficiency of LMFP. Synergistic buffering effects enabling faster charging have also been highlighted. These blends benefit from the compatibility of similar discharge potential of the two materials (~ 3 -4.2 V). Thus, a new taxonomy of cathode materials is coming online, with virtually infinite variations (Mn/Fe and NMC/LMFP ratios), for which the key performance metrics have not yet been well defined or understood. The advantages and disadvantages of each necessitate the optimisation of cathode chemistry for each distinct application e.g. high Mn content LMFP particularly suited for energy dense systems, while lower Mn content (or even simply LFP) may be more suited to fast charging use cases.