Electrostatic Self‐Assembly to Construct MXene@PS@CFx Electrode for High Power Density Lithium Primary Cells

The low power density has emerged as a pivotal challenge impeding the broader application of fluorinated carbon (CFx). Herein, a strategy for the fabrication of MXene@PS@CFx electrodes is proposed through electrostatic self-assembly. The method leverages polystyrene (PS) microspheres as a sacrificial template to introduce MXene onto the CFx surface via electrostatic interactions. The surface ─OH groups of MXene are harnessed to modulate and weaken the C─F bonds, ultimately yielding an electrode enrich with C─F semi-ionic bonds and sp2 C═C bonds. Atomic force microscope (AFM) visualization techniques monitor the cathode interface under various states of charge (SOC), revealing the reaction kinetics mechanisms of the cathode in CFx cells. The modified material demonstrates a lower height distribution and moderate roughness which facilitates the availability of additional reaction sites and effectively mitigates volume expansion. Consequently, the MXene@PS@CFx electrode demonstrates superior rate performance, achieving a remarkable energy density of 852 Wh kg⁻¹ at a high-power density of 10692 W kg⁻¹. These exceptional electrochemical properties underscore the efficacy of the modification strategy, offering meaningful insights to enhance the power density in primary lithium cells.