Oxides in the NixMn0.5-x/2Co0.5-x/2-O system were investigated as precursors in the all-dry synthesis of NMC622 (LiNi0.6Mn0.2Co0.2O2). Single-phase spinel precursors in this system were found to have the highest compositional homogeneity. To synthesize NMC, NixMn0.5-x/2Co0.5-x/2-O precursors were heated with Li2CO3 and NiO (to attain the correct NMC stoichiometry) in air or oxygen. This represents a different strategy in NMC synthesis compared to conventional hydroxide precursors that have the same composition as the final NMC. The most homogeneous and best performing NMC (171.9 mAh g−1 with 90% after 183 cycles) were obtained by using precursors that were essentially single-phase cubic spinel (0.070 ≤ x ≤ 0.091 in NixMn0.5-x/2Co0.5-x/2-O) even though such precursors had compositions that had significantly less Ni content than the target NMC622 composition. These findings demonstrate an alternate route for obtaining compositional homogeneity in NMC all-dry synthesis.

中文翻译：

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[Ni,Mn,Co]3O4 尖晶石前驱体全干法合成 NMC

研究了 NixMn0.5-x/2Co0.5-x/2-O 体系中的氧化物作为全干法合成 NMC622 (LiNi0.6Mn0.2Co0.2O2) 的前体。发现该系统中的单相尖晶石前体具有最高的成分均匀性。为了合成 NMC，将 NixMn0.5-x/2Co0.5-x/2-O 前体与 Li2CO3 和 NiO 在空气或氧气中加热（以获得正确的 NMC 化学计量）。与具有与最终 NMC 相同组成的传统氢氧化物前体相比，这代表了 NMC 合成中的不同策略。最均匀且性能最佳的 NMC（171.9 mAh g−1，183 次循环后容量为 90%）是通过使用基本上是单相立方尖晶石的前体获得的（NixMn0.5-x/2Co0.5- 中 0.070 ≤ x ≤ 0.091） x/2-O)，尽管此类前体的组成的 Ni 含量显着低于目标 NMC622 组成。这些发现证明了在 NMC 全干合成中获得成分均质性的替代途径。