Electrostatic Self‐Assembly to Construct MXene@PS@CF _x 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 (CF_x). Herein, a strategy for the fabrication of MXene@PS@CF_x electrodes is proposed through electrostatic self-assembly. The method leverages polystyrene (PS) microspheres as a sacrificial template to introduce MXene onto the CF_x 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 CF_x 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.