Mechanism and Primitive Description

The Ni-MH electrochemical primitive operates on the reversible interconversion of three condensed-phase materials. At the negative electrode, an AB5- or AB2-type intermetallic alloy (commonly LaNi5 derivatives or Ti-Zr-V-Ni systems) absorbs and desorbs atomic hydrogen as a metallic hydride; the storage mechanism is interstitial occupation of the alloy lattice with formal hydridic character. At the positive electrode, nickel hydroxide Ni(OH)2 oxidizes to nickel oxyhydroxide NiOOH on charge and reduces back on discharge; the storage mechanism is solid-state proton insertion into a metal-oxide framework. Between the two electrodes, an aqueous solution of potassium hydroxide (typically 30 percent by mass KOH, sometimes with LiOH additive) conducts hydroxide ions and supports the charge-transfer chemistry at both interfaces.

The disclosed carbon-bound cell replaces every one of these three primitives. Both electrodes are constructed from non-metallic carbon: graphenic, carbonaceous, or composite carbon scaffolds engineered for the binding and release of the active species. Hydrogen is stored not as a metal hydride but as a covalent C-H bond on the carbon scaffold; oxygen is stored not as a metal oxide-hydroxide but as a covalent C-O bond, in a chemically distinct functional environment. The electrolyte is not bulk aqueous KOH; instead, ionic conduction proceeds through a non-bulk, non-aqueous medium that does not flood the electrode pores in the manner characteristic of Ni-MH.

Each substitution moves the cell across a categorical architectural boundary rather than along a continuum of optimization. A Ni-MH cell with a different alloy is still a Ni-MH cell; a Ni-MH cell with a modified KOH concentration is still a Ni-MH cell. The disclosed cell is not a Ni-MH cell with parameter changes; it is a cell whose three constitutive primitives are categorically other.

Operating Parameters and Engineering Envelope

Ni-MH cells operate at a nominal cell voltage of 1.2 V, deliver gravimetric energy densities in the 60 to 120 Wh/kg range, and tolerate broad temperature envelopes (-20 C to +60 C) at the cost of high self-discharge and well-known memory-related capacity loss in early-generation chemistries. Cycle life is bounded by alloy pulverization on hydrogen sorption-desorption, by nickel-electrode passivation, and by electrolyte loss through venting on overcharge. The aqueous electrolyte imposes a freezing-point lower limit and a vapor-pressure upper limit, and necessitates pressure-relief venting that bounds the achievable hermeticity.

The disclosed carbon-bound cell sits in a categorically different parameter regime. Cell voltage, energy density, and rate capability are governed by the C-H and C-O bond energetics, by the local environment of the binding sites on the carbon scaffold, and by the kinetics of the non-bulk ionic transport medium, not by the M-H and Ni-O-H thermodynamics that fix Ni-MH performance. The absence of bulk aqueous electrolyte removes the freezing-point and vapor-pressure constraints that bound Ni-MH and admits hermetic sealing without pressure-relief provisions characteristic of aqueous-alkaline cells.

Engineering-envelope parameters that further distinguish the disclosed cell include the absence of dendritic or pulverization failure modes characteristic of metal-hydride alloys, the absence of electrolyte-leakage and corrosion considerations characteristic of concentrated KOH systems, and the elimination of nickel as a critical material from the bill of materials. The disclosed cell does not require rare-earth or platinum-group constituents that drive Ni-MH alloy cost.

Alternative Embodiments

The disclosed cell admits embodiments differentiated by the carbon scaffold morphology (graphenic flake, foam, fiber, or composite), by the surface functionalization that establishes the binding-site density, and by the non-bulk ionic medium. Embodiments are also differentiated by the geometry of the cell, planar, cylindrical, prismatic, or structural, including embodiments in which the cell is integrated into load-bearing concrete or polymer matrices in the substrate-mode configuration.

None of these embodiments approach Ni-MH architecture. There is no embodiment in which an alloy negative electrode and a nickel-hydroxide positive electrode are simultaneously present with a bulk KOH electrolyte; the disclosure does not contemplate such a hybrid because each of the three primitive substitutions is independently load-bearing. An embodiment that retains aqueous KOH but uses carbon electrodes is outside the disclosed scope; an embodiment that uses non-bulk electrolyte but retains an alloy or nickel-oxide electrode is likewise outside scope. The disclosed embodiments converge on a coherent design point, sealed, all-carbon, covalent-storage, non-bulk-medium, and diverge from Ni-MH at every structural axis simultaneously.

Composition with Adjacent Primitives

The disclosed cell composes with the carbon-substrate-flow primitives that source and credential the structural carbon, with the substrate-mode storage primitive that integrates cells into load-bearing elements, and with the credentialed-lineage attestation that anchors the carbon's provenance from feedstock through pour. The Ni-MH class composes with none of these adjacent primitives in any meaningful sense: nickel-hydroxide and rare-earth alloys are not produced by flash graphenization of biomass, are not credentialed under the disclosed lineage schema, and are not load-bearing structural materials.

The architectural boundary therefore propagates outward from the cell itself: a Ni-MH cell does not admit substrate-mode integration or credentialed-carbon provenance because its constitutive materials do not participate in the carbon-flow ecosystem. The disclosed cell is purpose-built to compose with that ecosystem and is structurally inseparable from it.

Prior-Art Distinctions

The Ni-MH class is well-developed in the prior art and includes hydrogen-storage-alloy cells of related construction (e.g., Ni-Zn, Ni-Fe, Ni-Cd by analogy at the positive electrode; AB5, AB2, A2B, and BCC-solid-solution alloys at the negative electrode). All of these cells share the three-primitive architecture: metal-based hydrogen storage, metal-oxide-based oxygen storage, and bulk aqueous alkaline electrolyte. Distinctions among them are intra-class, addressing alloy composition, electrode formulation, separator selection, and electrolyte additive packages.

The disclosed carbon-bound cell does not occupy this class. It does not store hydrogen in a metal lattice; it does not store oxygen in a metal-oxide; it does not flood a porous separator with aqueous alkaline electrolyte. A skilled artisan applying conventional taxonomy to the disclosed cell would not classify it as Ni-MH, would not classify it as hydrogen-storage-alloy, and would not classify it within any of the analogous metal-electrode aqueous-alkaline classes.

The distinction is not merely semantic. The failure modes, the materials supply chain, the manufacturing footprint, the integration topology, and the end-of-life pathway all differ from the Ni-MH class because the constitutive primitives differ.

Disclosure Scope

The disclosure scope of the carbon-bound cell under Provisional 64/052,368 covers cells in which both electrodes are non-metallic carbon, in which both active species are stored as reversible covalent bonds to that carbon, and in which the ionic conduction medium is non-bulk and non-aqueous. The scope is bounded affirmatively by the joint presence of these three primitives and bounded negatively by the absence of any single Ni-MH-class primitive (metal-hydride alloy, metal-oxide-hydroxide, bulk aqueous alkaline electrolyte).

Scope is open across the carbon-scaffold morphology, the surface-functionalization chemistry that defines binding sites, the non-bulk ionic medium, the cell geometry, and the integration topology (discrete-cell, modular, or substrate-mode). Scope expressly contemplates embodiments in which the cell is integrated into load-bearing structural elements, embodiments in which the cell is networked into building-scale arrays, and embodiments in which credentialed-carbon provenance is preserved through the lifecycle.

Scope does not extend to any cell that retains a metal-hydride or hydrogen-storage-alloy negative electrode, that retains a nickel- or related-metal oxide-hydroxide positive electrode, or that retains a bulk aqueous alkaline electrolyte, regardless of any carbonaceous additive or coating that may be present in such a cell. Hybrid embodiments that pair carbon electrodes with aqueous KOH, or carbon scaffolds with metal-hydride alloys, fall outside the disclosed primitive set.

The class non-equivalence with Ni-MH is therefore not contingent on a single distinguishing feature but is established by three independent and simultaneous architectural substitutions, any one of which would be sufficient to remove the disclosed cell from the Ni-MH class and all three of which are present.

The disclosure further records that the structural distinctions between the disclosed cell and the Ni-MH class are intentional and load-bearing. Each substitution, carbon electrodes for metal alloy and metal-oxide-hydroxide, covalent C-X storage for metal-X compound formation, non-bulk non-aqueous medium for bulk aqueous KOH, was selected to enable a use case (substrate-mode integration into structural elements with credentialed-carbon provenance) that the Ni-MH primitive set categorically cannot support. The disclosed scope therefore extends to embodiments in which the cell is integrated into cementitious or polymer matrices, embodiments in which the cell is networked into building-scale arrays under credentialed-lineage governance, and embodiments in which the cell shares its carbon-scaffold provenance with the surrounding structural carbon. None of these embodiments has any analog in the Ni-MH literature, because the Ni-MH primitive set is incompatible with the structural-integration and credentialed-flow contexts that the disclosed cell is built to occupy.