frontiers / frontier
The frontier at a glance, assembled from accepted state: what the frontier holds, the strongest findings with their evidence, and the open and contested edges. Copy it straight into a grant, paper, or lab-meeting doc.
Brief export contract
A brief is a portable package over frontier state. It helps humans write, but the frontier remains the inspectable record.
accepted slice
Significance should come from accepted findings first, with fallback labels when no formal acceptance exists yet.
inspect findings →
evidence table
Finding text, confidence, source citation, caveats, and contested edges should remain close to the exported finding.
find evidence →
open work
Open questions, contested findings, gaps, and missing sources stay in the packet instead of being smoothed away.
open workbench →
release return
A grant, paper, or lab note should be able to return to the frontier hash, source package, event log, and proof packet.
check trust →
strongest findings (none formally accepted yet)
bibliography · 15 sources
export · markdown
# Solid-state battery electrolytes This frontier holds 16 findings (0 accepted) over 15 sources. ## Significance - Sulfide electrolytes (Li10GeP2S12, Li6PS5Cl argyrodites) deliver the highest ionic conductivity among solid electrolytes—up to 25 mS/cm at room temperature—enabling practical charge/discharge rates. (reviewer:will-blair 2022) - Sulfide electrolytes are hygroscopic and release toxic hydrogen sulfide gas upon moisture exposure, requiring dry-room handling and creating supply-chain barriers to high-volume manufacturing. (reviewer:will-blair 2024) - Oxide electrolytes (LLZO garnet Li7La3Zr2O12) are mechanically rigid and chemically stable but cannot maintain conformal contact with electrodes without external pressure, leading to high interfacial resistance that limits practical energy density. (reviewer:will-blair 2024) - Interfacial resistance at the electrode-electrolyte boundary dominates total cell impedance in oxide electrolytes; chemical/electrochemical side reactions form passivating interphases that block Li+ transport. (reviewer:will-blair 2016) - Polymer electrolytes (polyethylene oxide, PEO) exhibit lower ionic conductivity (~10⁻⁴ S/cm at 60°C) but superior mechanical compliance and dendrite suppression due to viscoelastic deformation accommodating lithium plating. (reviewer:will-blair 2025) - High electronic conductivity within solid electrolytes is the origin of lithium dendrite formation; electronic transport through the electrolyte reduces the effective overpotential, enabling localized plating at grain boundaries. (reviewer:will-blair 2019) - QuantumScape's anode-free architecture (QSE-5) with engineered separator produces automotive B-sample cells achieving >800 Wh/L energy density and 10–80% charging in <15 minutes, validating sulfide electrolyte manufacturability at small scale. (reviewer:will-blair 2024) - Oxide electrolytes can undergo oxidative degradation at high voltage (>4.3 V vs Li/Li+), consuming electrolyte and increasing interfacial impedance, limiting compatibility with high-energy cathode materials. (reviewer:will-blair 2024) - The critical current density (CCD)—maximum current at which dendrites do not propagate—varies from 1–5 mA/cm² for oxide electrolytes to 10–50 mA/cm² for optimized sulfide electrolytes, a 10-fold gap that limits practical deployment. (reviewer:will-blair 2021) - The measurement of sulfide electrolyte ionic conductivity is complicated by stack pressure sensitivity; reported values at low pressure (<1 MPa) are often 50% lower than those under high laboratory pressure (>500 MPa), inflating apparent conductivity. (reviewer:will-blair 2021) - Dendrite penetration through solid electrolytes occurs not as monolithic whisker growth but as void formation at the anode-electrolyte interface combined with partial electrochemical dissolution of the electrolyte itself. (reviewer:will-blair 2022) - Interfacial engineering (protective coatings, interlayers, doping) can increase critical current density in garnet electrolytes from ~3 mA/cm² to >10 mA/cm², but requires precise, scalable coating processes not yet industrialized. (reviewer:will-blair 2022) ## Contested - Sulfide electrolytes (Li10GeP2S12, Li6PS5Cl argyrodites) deliver the highest ionic conductivity among solid electrolytes—up to 25 mS/cm at room temperature—enabling practical charge/discharge rates. - Sulfide electrolytes are hygroscopic and release toxic hydrogen sulfide gas upon moisture exposure, requiring dry-room handling and creating supply-chain barriers to high-volume manufacturing. - Solid-state battery cost remains 2–5x that of liquid-ion chemistry, driven by electrolyte synthesis complexity, drying/handling costs, and low manufacturing maturity; commercialization hinges on scale economies and process innovation.