From Atoms to Cells: First‐Principles Mapping of MXene–TMD Heterostructures for Next‐Generation Metal‐Ion Batteries

MXene–transition metal dichalcogenide (TMD) heterostructures combine tunable surface terminations with redox‐active layered hosts, offering a versatile platform for next‐generation metal‐ion batteries. This review introduces an evidence‐graded, atoms‐to‐cells framework that maps interface‐controlled descriptors—termination chemistry, interlayer spacing, charge redistribution, and mechanical compliance—from atomic‐scale computation to cell‐level performance across lithium, sodium, potassium, zinc, magnesium, calcium, and aluminum chemistries. Density functional theory (DFT) evidence is compiled separately from experimental evidence to enforce falsifiability: each design‐rule claim is graded as convergent, computation‐led, experiment‐led, or open. Computation reveals that MXene termination identity (–O/–OH/–F) shifts work functions by up to ∼3.5 eV and dominates adsorption energetics, diffusion barriers, and interfacial stability, while TMD phase (2H vs. 1T/1T′) controls conductivity and ion accessibility. Experimentally, MXene–TMD architectures consistently improve rate capability and cycling stability through restacking suppression and electronic percolation, yet most demonstrations remain at low areal loading, and interface persistence under realistic conditions is rarely verified. Critical gaps—including MXene oxidation drift, cost‐performance parity with carbon scaffolds, and insufficient operando validation—are identified alongside a decisive roadmap prioritizing termination‐aware design, thick‐electrode benchmarking, and closed‐loop descriptor‐to‐observable validation chains for practical deployment.