Solid-state & semi-solid Li-ion battery innovation — patent-derived benchmarking across 40 company portfolios
The top demonstrated values cluster at 7–9 × 10⁻³ S/cm, and almost all of them come from gel-polymer formulations where the polymer is the structural matrix but a bulk liquid component (carbonate or ether solvent) carries most of the ion transport. STRONG
LG Energy holds the leading demonstrated value at 9.03 × 10⁻³ S/cm at 25 °C, achieved with a branched PCTFE-graft-acrylate copolymer at ~1 wt % loading in 1 M LiPF₆/EC:EMC. MODERATE The value is reproduced across two sister filings (EP 3965203 A1 and EP 3961784 A1) and reaches a similar but lower number in a third LG variant with siloxane side chains.
Two entries warrant particular attention beyond the headline number. CATL's supramolecular ionic-liquid design is the only entry in the top tier that was editorially singled out as the rank-1 result in its review cycle — π-stacked benzophenanthrene cores form columnar ion-transport channels, demonstrated with NMC + Li-metal coin cells. MODERATE Nuvvon's PVDF/CN-PVA polymer-in-salt is the only top-tier entry that is genuinely solvent-free, and the only one with full-cell LFP cycling data — editorially highlighted as a rank-2 result and notable for room-temperature performance (1.6 × 10⁻³ S/cm at 25 °C; 7.97 × 10⁻³ S/cm at 80 °C). MODERATE
Important caveat on like-for-like comparison. The ranking mixes electrolyte forms that behave very differently in a cell. The 9 × 10⁻³ end of the scale is essentially gel polymer with ≥50 wt % liquid in the formulation — the polymer's contribution to ion transport is structural, not the primary conduction mechanism. Genuinely dry polymer electrolytes in this file (no liquid solvent) cap around 1–3 × 10⁻³ S/cm at 25 °C. The temperature axis matters too — Nuvvon and Panasonic only reach 7 × 10⁻³ S/cm at 60–80 °C; at 25 °C their values are 2–3× lower.
| Rank | Company / patent | IC (S/cm) | T (°C) | SCALE |
SHOWN-WITH |
Form | Conf. |
|---|---|---|---|---|---|---|---|
| 1 | LG Energy EP 3965203 A1 (EPO / Google) |
9.03e-3 | 25 | lab-only | with-cell-data |
anode=graphite cathode=NMC811 format=pouch |
Gel polymer (PCTFE-g-mPEGA in 1 M LiPF₆/EC:EMC 3:7) | MODERATE |
| 2 | LG Energy EP 3961784 A1 (EPO / Google) |
9.03e-3 | 25 | lab-only | with-cell-data |
anode=graphite (implied) cathode=NMC811 format=coin |
Gel polymer (PCTFE-g-PA, sister application) | MODERATE |
| 3 | WeLion CN 120895717 A (EPO / Google) |
8.96e-3 | RT | lab-only | anode=generic format=symmetric (SS/SE/SS) |
In-situ expansion-polymerized gel (LiPF₆/EC:DMC:EMC); near-zero volume shrinkage (−0.16 %) | MODERATE |
| 4 | SES AI WO 2024119495 A1 (EPO / Google) |
8.81e-3 | 25 | lab-only | with-cell-data |
anode=Li-metal cathode=NMC format=coin |
Crosslinked vinyl-sulfone gel (LiPF₆/VC/DMC/MEC; polymer ≤50 wt %) | MODERATE |
| 5 | Factorial WO 2026055175 A1 (EPO / Google) |
7.97e-3 | 25 | lab-only | with-cell-data |
anode=Li-metal cathode=NMC811 format=pouch |
Gel polymer in ether solvent (LiFSI/DEE/BTFM + poly-trioxane, in-situ ring-opening) | MODERATE |
| 6 ▲ | Nuvvon US 2024243355 A1 (EPO / Google) |
7.97e-3 (80 °C) 1.64e-3 (25 °C) |
25 / 80 | lab-only | with-cell-data |
anode=Li-metal cathode=LFP format=coin |
Dry polymer-in-salt (PVDF + CN-PVA + LiTFSI, no solvent); roll-to-roll compatible | MODERATE |
| 7 | LG Energy WO 2024228578 A1 (EPO / Google) |
7.9e-3 | 25 | lab-only | anode=Li-metal format=symmetric (no cycling) |
Sulfonimide polymer film, wetted with EC/PC 1:1 for measurement; t⁺ = 0.94 | THIN |
| 8 | CATL CN 120453470 A (EPO / Google) |
7.5e-3 | 25 | lab-only | with-cell-data |
anode=graphite cathode=NCM622 format=pouch |
Gel polymer with cyclic groups in 1 M LiPF₆/EC:DMC; t⁺ = 0.45 | MODERATE |
| 9 ▲ | Panasonic WO 2022145318 A1 (EPO / Google) |
7.1e-3 (60 °C) 2.9e-3 (25 °C) |
25 / 60 | lab-only | format=symmetric (SS/SE/SS); no real cells |
Dense sulfonated polysaccharide (cellulose-based); no liquid | THIN |
| 10 ★ | CATL WO 2022021231 A1 (EPO / Google) rank-1 · 2022-02-27 |
6.5e-3 (IL only) 2.4e-3 (membrane) |
25 | lab-only | with-cell-data |
anode=Li-metal cathode=NMC811 format=coin |
Supramolecular ionic-liquid (π-stacked benzophenanthrene) in PEO/PVDF matrix + LiTFSI | MODERATE |
| 11 | LG Energy US 2022025126 A1 (EPO / Google) |
6.5e-3 | 25 | lab-only | with-cell-data |
cathode=NMC811 format=coin |
Gel polymer (PCTFE-g-(PDMS+acrylic) in EC:EMC); LG family member | MODERATE |
Two patents are flagged as the rank-1 result in their respective review cycles — the highest editorial weight in the dataset — plus one rank-2 highlight worth pulling forward.
WO 2022021231 A1 (EPO / Google)
Benzophenanthrene cores self-organize via π-π stacking into columnar ion-transport channels; demonstrated with NMC811 + Li-metal coin cells at 6.5 × 10⁻³ S/cm. The SME called this a structural differentiator, not just a number — most "high-IC polymer" claims at the time relied on heavy liquid content, while this design delivers high conductivity from a hot-pressed pellet through molecular-architecture choices. Reservation in the rationale: still lab-only at coin-cell scale; columnar order under industrial processing is unproven.
WO 2022203405 A1 (EPO / Google)
The 3.18 × 10⁻³ S/cm value comes entirely from ab-initio molecular dynamics simulation of Li⁺ hopping via quinone C=O coordination sites — no physical cells assembled. The SME highlighted the conceptual originality: a polymer-free, solid two-component design. Excluded from the demonstrated ranking. Confidence grade strictly THIN despite the editorial weight, in line with the LISE-C-7 rule that tier weight does not by itself raise the grade.
US 2024243355 A1 (EPO / Google)
The only top-IC entry that genuinely dispenses with liquid solvent. CN-PVA's dielectric constant (~15) boosts salt dissociation in the polymer-in-salt regime; the membrane is calendered to 1.7 g/cm³ and demonstrated in LFP coin cells. Room-temperature value 1.64 × 10⁻³ S/cm (35 wt % PVDF / 5 wt % CN-PVA / 60 wt % LiTFSI variant); 7.97 × 10⁻³ S/cm at 80 °C. The architecture is also roll-to-roll-compatible, which matters for scale-up.
GM CN 119905648 A (EPO / Google) claims ≥8.5 × 10⁻³ S/cm at 60 °C for a PEC + solvated-ionic-liquid + LiTFSI gel, but the file explicitly notes "no experimental results identified — claim threshold only; no measured cycling/retention/rate/cell-format data." Surfaced for completeness; not directly comparable to measured values.
LG Energy WO 2022203405 A1 is excluded from the demonstrated ranking but kept in the editorial highlights above on account of its Tier-1 weight. All conductivity values come from AIMD simulation at 300 K. Stated under the LISE-C-7 calibration discipline: when uncertain, downgrade — computational-only ranks behind even minimal experimental data.
Category 5 ("polymer/oligomer predominant component") admits both dry polymer electrolytes and gel polymers, and the highest values come from designs that sit very close to liquid electrolyte. If "highest polymer ionic conductivity" was meant to exclude formulations with bulk liquid solvent, the leaders shift to:
Within that subset, room-temperature dry polymer SE in this file caps around 1–3 × 10⁻³ S/cm, well below the gel-polymer leaders. The structural-versus-conduction-mechanism distinction is the most consequential framing choice for a product- or process-definition decision built on these numbers.
Filtered column A = Category 5 across all 40 company tabs (371 patents, 28 companies). Ran an anchor-key extraction of every IC= value from column J of those 371 rows — 164 patents carry an IC value; the remaining 207 cover process, electrode, or other angles without a polymer-electrolyte IC datapoint. Ranked by best parsed numerical value; read the full column J for the top 15 to verify units, temperature, conditions, and demonstrated stack. Sub-agent dispatch not used — single-pass extraction was within the row budget.
Active source tier: Tier 1 (file + scientific reasoning only); no web search. SME editorial overlay applied: rank-1 highlights surfaced for CATL WO 2022021231 A1 (2022-02-27 cycle) and LG Energy WO 2022203405 A1 (2022-10-18 cycle); rank-2 highlight surfaced for Nuvvon US 2024243355 A1 (2024-07-30 cycle). Column-O rationales read for all three. The overlay can be disabled with "ignore the SME tiers".
Reader lens: CTO default. Confidence grades: STRONG reserved for claims with multi-patent corroboration plus pilot/industrial-parameter evidence — none meet that bar here since the entire Category 5 cohort is lab-only. MODERATE applied to single-patent values with credible KPI + with-cell-data; THIN applied where data is symmetric-cell-only, computational, or claim-only.
Citation verification ran on all 11 ranked entries plus the three editorial highlights and the excluded GM filing — all values, temperatures, and cell stacks match the source row character-for-character.
Quality note: an early parsing pass surfaced two artifacts (Qingtao CN 118448714 A and one Factorial entry) where exponential notation collided with a fallback regex; both were corrected before ranking. Sample size adequate for this question.
lab-only, with with-cell-data noted where the patent demonstrated actual test cells using the disclosed materials.