Mechanism
The disclosed cell encodes its instantaneous state of charge along two physically distinct but coupled state variables. The first state variable is the chemical-bond axis. On the first electrode, the bond-axis coordinate is the fraction of carbon sites that carry a C-H bond; on the second electrode, the coordinate is the fraction of sites that carry a C-O bond. Charging the cell drives hydrogen onto the first electrode and oxygen onto the second electrode, populating these sites; discharging the cell strips the bonds and returns the constituent species to the electrolyte phase. The bond-axis coordinate is bounded between zero (fully discharged) and a saturation fraction approaching unity (fully charged) and is a continuous, monotonic function of charge transferred.
The second state variable is the electrode-density axis. As bonds populate the carbon framework, mass is added to the electrode and the electrode bulk density increases. Simultaneously, the bond-saturated framework is held under inter-particle compressive strain by the cell housing, with the strain itself a function of bond-loaded mass and of the geometric constraint imposed by the cell stack. The density-axis coordinate therefore comprises both the bulk density of the bond-saturated electrode and the elastic compressive strain stored in the inter-particle contact network. Energy is stored along the density axis as elastic strain energy in the compressed solid framework and as gravitational and configurational energy in the densified electrode mass. The two axes are physically coupled: a step along the bond axis produces a step along the density axis, but the coupling is non-degenerate, so each axis carries information about the cell state that cannot be inferred from the other alone.
Operating Parameters
Operating parameters are specified separately on each axis and jointly across the coupled pair. On the bond axis, the saturation fraction admits values between approximately 0.05 (lower discharge bound, below which kinetics become rate-limiting) and approximately 0.85 to 0.95 (upper saturation bound, above which incremental sites become inaccessible). The first electrode operates between bond-fraction limits set by C-H formation thermodynamics and by the available hydrogen activity in the electrolyte; the second electrode operates between limits set by C-O formation thermodynamics and the corresponding oxygen activity.
On the density axis, the bulk density of bond-saturated electrodes admits values typically in the range 0.4 to 1.6 g/cm³ for carbon-class frameworks, and inter-particle compressive strain admits values up to a few percent before the framework yields. The cell housing must enforce a constraint that holds the electrode within the admissible strain window across the full bond-axis swing. Joint operation requires that any operating point lie within the two-dimensional admissibility region defined by the simultaneous constraints on both axes, and the cell controller monitors trajectories through this region to avoid excursions that would damage the framework or strand stored energy.
Alternative Embodiments
Several alternative embodiments of the joint-encoding primitive are disclosed. In a first embodiment, the bond axis is implemented with C-H storage on a graphene-class first electrode and C-O storage on an oxidized graphene-class second electrode, with the density axis implemented through a rigid cell housing that enforces a fixed external volume so that bond-loaded mass directly produces compressive strain. In a second embodiment, the cell housing admits a controlled external displacement, so that the density-axis coordinate can be operated independently of the bond axis up to the limit imposed by the mechanical coupling.
In a third embodiment, the two axes are operated asymmetrically: the bond axis swings across its full range while the density axis swings across only a fraction of its range, trading some incremental capacity for reduced mechanical wear. In a fourth embodiment, additional state variables, for example, electrolyte-side ionic concentration, are co-encoded with the bond and density axes, extending the architecture from two-axis to three-axis joint encoding while preserving the substantive additivity of the original two axes.
Composition
The composition of a joint-encoded cell comprises a first carbon electrode configured for C-H storage, a second carbon electrode configured for C-O storage, an electrolyte phase that supports proton and oxygen-bearing species transport between the electrodes, and a cell housing that enforces a defined mechanical constraint on the electrode stack. Each electrode carries a credentialed property surface that records both its bond-axis admissibility window and its density-axis admissibility window, and the cell as a whole carries a joint admissibility surface that records the two-dimensional region within which combined bond and density coordinates are operationally permitted. The cell controller is configured to read both axes, typically by measuring open-circuit voltage for the bond axis and by measuring stack height or inter-particle pressure for the density axis, and to compute the stored energy as the substantively additive sum of the two axis contributions.
Prior-Art Distinction
Prior-art electrochemical cells encode state of charge along a single axis: a redox-couple axis for batteries, a surface-charge axis for capacitors, or a chemical-bond axis for hydrogen-storage and similar systems. Prior-art cells treat any density change accompanying the charge cycle as a parasitic effect to be minimized: for example, by mechanically over-constraining the cell to suppress strain, or by selecting electrode chemistries with low volumetric change. Energy associated with such density changes, where it exists, is discarded into the housing or into mechanical wear. The disclosed joint-encoding primitive distinguishes by treating the density-axis change as a co-equal storage variable rather than a parasitic effect, by sizing the housing constraint to admit and recover the density-axis energy, and by reciting the additive contribution of the density axis in the cell's energy capacity. The result is a cell whose total stored energy exceeds the bond-axis-only capacity by the integral of the density-axis contribution across the operational swing.
Disclosure Scope
The disclosure recites joint chemical-bond and electrode-density encoding as a storage primitive of the disclosed cell architecture. The recitation covers any cell in which the chemical-bond and electrode-density coordinates are jointly used as state-of-charge variables, in which both axes contribute substantively and additively to stored energy, and in which the cell housing and controller are configured to admit, measure, and recover the density-axis contribution. Cells that operate only on the bond axis, that suppress the density-axis swing, or that fail to recover the density-axis energy as useful work are outside the disclosed primitive. The disclosure further covers downstream claims directed to multi-cell stacks, density-controlled charging protocols, and joint-axis credentialing surfaces that record verified operation within the two-dimensional admissibility region.
