Abstract Traditional slurry‐coated electrodes suffer from limitations such as low electrode energy density.This study proposes a self‐supporting composite electrode construction strategy that simplifies the preparation process. A carbon nanotube (CNT) conductive network is in situ constructed on the surface of lithium manganese oxide (LMO) by freeze‐drying, which has both support and ion transport functions. The unique characteristics of 1D conductive materials effectively avoid the interlayer stacking effect of 2D materials, reduce internal resistance, and improve charge and discharge performance. It is worth noting that the active material content of the composite electrode exceeds 90%, and less conductive material is required, thereby reducing costs. The composite electrode achieves an extremely high load of up to 45 mg cm −2 and a discharge specific capacity of 125 mAh g −1 , giving full play to the charge and discharge specific capacity of LMO, so that the actual specific capacity reaches 84.5% of the ideal specific capacity. Moreover, this preparation process is simpler and more controllable than traditional slurry coating and drying methods, and can be produced on a large scale and at low cost, with strong practical application potential.