Heterostructured cathode materials have been developed to mitigate degradation. The most common approach are core-shell arrangements, where the core phase provides high energy storage and is protected by a thin shell of a different material to stabilize it against its environment. Classic examples include Albased coatings on various LiNMC compositions. However, the sophistication of cathode heterostructures has grown exponentially in the past decade. One widespread approach driving the design of heterostructures targets a reduction of the interfacial strain when the core and shell have significant epitaxial mismatches through smooth compositional gradients introduced during the growth of the mixed metal precursors. The pinnacle of this approach are materials with a full concentration gradient, where, for instance, the precursors are designed with a linearly decreasing Ni and increasing Mn concentration toward the secondary particle surface. In this case, the increase in Mn confers thermal stability while the smooth transition between different NMC compositions enhances structural stability.