Electrical charge deposition modulates carrier mobility in electronic devices and governs interfacial processes such as frictional energy dissipation and triboelectric power generation. Selective charge deposition on 2D materials enables logic and memory functions, but controlling charge transfer and trapping remains a challenge. Here, we report an unconventional contact electrification mechanism activated at a sliding structural superlubric interface between highly ordered pyrolytic graphite and h-BN. Spatially controlled charge deposition is achieved through mechanical manipulation at the sliding front in a reversible way, while face-to-face contact remains intact even under pressures exceeding the strength of most materials. First-principles calculations reveal that edge contact facilitates electron transfer, with charge deposition driven by a chemical potential difference across the graphite/h-BN interface and stabilized by surface adsorbates.