Significantly Improving Lithium-Ion Transport via Conjugated Anion Intercalation in Inorganic Layered Hosts

Layered hydroxides (LHs) have emerged as an important class of functional materials owing to their unusual physicochemical properties induced by various intercalated species. While both the electrochemistry and interlayer engineering of the materials have been reported, the role of interlayer engineering in improving the Li-ion storage of these materials remains unclear. Here, we rationally introduce pillar ions with conjugated anion dicarboxylate groups, cobalt oxalate ions ([CoOx2]2-), into the interlayers of Co(OH)2 nanosheets [denoted as I-Co(OH)2 NSs]. The pillar ion guarantees excellent structural stability, high electrical conductivity, and accelerated Li-ion diffusion. The structure delivers high-rate cycling performance for lithium-ion batteries. This work provides insights for the design of LH-based high-performance electrode materials by a rational interlayer-engineering strategy.