AIDT 온디바이스 STEM 전고체 배터리 리튬 수지상(Dendrite) 응력 결합 버틀러-볼머 서보 엔진

using System;
using System.Runtime.CompilerServices;

namespace ZeliDesk.Stem.Electrochemistry
{
    public readonly ref struct BatteryInterfaceState
    {
        public readonly float TipCurrentDensityMaCm2;
        public readonly float EffectiveOverpotentialMv;
        public readonly float AppliedStackPressureMpa;
        public readonly bool IsDendriteSuppressed;

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public BatteryInterfaceState(float jTip, float etaEff, float pStack, bool suppressed)
        {
            TipCurrentDensityMaCm2 = jTip;
            EffectiveOverpotentialMv = etaEff;
            AppliedStackPressureMpa = pStack;
            IsDendriteSuppressed = suppressed;
        }
    }

    public ref struct SolidStateBatteryDendriteServo
    {
        private const float FaradayConst = 96485.3f; // C/mol
        private const float GasConst = 8.314f;       // J/(mol*K)
        private const float TempK = 298.15f;         // 25 C
        private const float MolarVolumeLi = 1.3e-5f; // m^3/mol
        private const float J0Exchange = 1.2f;       // mA/cm^2

        private float _stackPressureMpa;
        private float _runningOverpotentialMv;

        public SolidStateBatteryDendriteServo(float initialPressureMpa = 5.0f)
        {
            _stackPressureMpa = MathF.Max(0.5f, initialPressureMpa);
            _runningOverpotentialMv = 25.0f;
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public BatteryInterfaceState UpdateServo(float chargeCurrentMaCm2, float targetPressureMpa, float dt = 0.0001f)
        {
            _stackPressureMpa += (targetPressureMpa - _stackPressureMpa) * (dt * 50.0f);

            // Stress-induced chemical potential offset: DeltaV = Omega_Li * sigma / F
            // sigma in Pa (1 MPa = 1e6 Pa)
            float stressPotentialOffsetV = (MolarVolumeLi * (_stackPressureMpa * 1.0e6f)) / FaradayConst;
            float stressPotentialOffsetMv = stressPotentialOffsetV * 1000.0f;

            // Effective overpotential at dendrite tip
            float nominalEtaMv = (chargeCurrentMaCm2 / J0Exchange) * 20.0f;
            float effectiveEtaMv = nominalEtaMv - stressPotentialOffsetMv;

            // Stress-coupled Butler-Volmer tip current
            float fOverRt = FaradayConst / (GasConst * TempK * 1000.0f); // 1/mV
            float jTip = J0Exchange * 2.0f * MathF.Sinh(0.5f * effectiveEtaMv * fOverRt);

            bool suppressed = effectiveEtaMv < 10.0f;

            return new BatteryInterfaceState(jTip, effectiveEtaMv, _stackPressureMpa, suppressed);
        }
    }
}