<p>Triboelectric nanogenerators (TENGs) are a transformative technology for harvesting mechanical energy, yet their practical output is often limited by the efficiency of charge collection and transport. While most research focuses on triboelectric layer pairings, this review asserts that the electrode is the pivotal component determining the final voltage outcome and overall device performance. This review article presents a comprehensive analysis of material and architectural trends in TENG electrodes, systematically evaluating their direct impact on voltage generation. The review charts the evolution from simple metallic foils to advanced functional electrodes incorporating high-conductivity nanomaterials, including carbon nanotubes (CNTs), graphene, and emerging 2D MXenes. Our analysis of recent literature demonstrates that the integration of these materials is the primary driver for enhancing surface charge density and achieving significant breakthroughs in output voltage. Concurrently, we deconstruct the performance gains achieved through architectural innovation, comparing fundamental single- and double-electrode designs with more complex multi-unit and freestanding configurations. A core finding is that optimal performance arises not from material selection alone, but from the synergistic engineering of the electrode’s composition and its physical structure. This work provides a critical roadmap for the rational design of high-performance electrodes, guiding future research toward developing TENGs with the high-voltage capabilities essential for self-powered electronics, wearables, and next-generation energy system.</p>