Triweekly Patent Update – Free Version

An all-solid-state battery forms a deep eutectic interfacial electrolyte in situ by depositing the hydrogen-bond donor and acceptor separately onto the positive electrode and the facing surface of the sulfide solid electrolyte membrane, then co-crystallizing them at the joined interface during thermal pressing.

First, an NCM811 positive electrode (15 mg/cm²) containing Li₆PS₅Cl (LPSC) catholyte (37 mass%), a fluoropolymer binder, and VGCF was rolled (250 MPa). Second, a toluene solution of succinonitrile (20 mass%) with dodecanethiol stabilizer was blade-coated onto the cathode (1 mg/cm²). Third, an LPSC / SEBS membrane (50 μm) was coated on its cathode-facing side with a DME solution of LiTFSI (donor : acceptor = 7 : 1 mol; 0.5 mg/cm²). Fourth, the coated faces were laminated, stacked with a Li-In alloy anode (50 μm), pressed (300 MPa), heated (70°C, 3 h), and re-pressed at 300 MPa.

Cells exhibit a first-cycle capacity of 193 mAh/g at 0.1 C and 162 mAh/g at 0.33 C, with capacity retentions of 98% after 10 cycles and 95% after 50 cycles (4.2–2.7 V vs Li-In). A control prepared without the donor and acceptor coatings delivers 175 mAh/g at 0.1 C, 130 mAh/g at 0.33 C, and 50% retention after 50 cycles. A second control applying succinonitrile and LiTFSI as a single premixed solution against a Li metal anode delivers 75% retention after 50 cycles.

Bamboo-derived carbonaceous material was acid-washed with 1 mol/L hydrochloric acid and 1 mol/L hydrofluoric acid (12 h each), water-rinsed, and dried at 80°C for 12 h to obtain a first carbon precursor. The precursor was soaked in a 30 mass% aqueous phenolic resin solution for 12 h, then hot-pressed at 140°C and 3.0 MPa for 10 min, filling macropores in the carbon framework with resin and yielding a second carbon precursor.

The second carbon precursor was carbonized at 800°C for 6 h under nitrogen flow (200 L/h) and pulverized by gas-flow milling to a D₅₀ of 10 μm. The carbon material was mixed with ethylboronic acid (6 mass% of the mixture) and heat-treated at 800°C for 4 h under nitrogen. Pyrolysis of the boron precursor introduces boron, oxygen, and additional carbon into the matrix: part of the boron forms boron carbide (B₄C) bonded into the carbon skeleton, and another part forms boron oxides on the matrix surface.

Silicon was deposited onto the boron-doped carbon matrix by CVD (chemical vapor deposition) at 450°C for 10 h under flowing silane (SiH₄, 5 L/min) and nitrogen (1 L/min). The resulting anode material contains 1.4 mass% boron and 3.10 mass% oxygen, and exhibits a relative particle strength (Cx) of 125.2 MPa and a powder conductivity of 1.21 S/cm at 20 kN.

In half-cells (1 mol/L LiPF₆ in ethylene carbonate (EC) / ethylmethyl carbonate (EMC), lithium counter electrode, 0.01–1.5 V), the anode material exhibits a discharge capacity of 1,792 mAh/g, a first cycle coulombic efficiency of 93.2%, an electrode thickness expansion of 32.1%, and a gas evolution of 5.3 cm³/kg/d after 50 cycles (1 C charge/discharge), as compared to 2,259 mAh/g, 85.4%, 45.3%, and 56.2 cm³/kg/d for a comparative material prepared without the boron doping step (B = 0, O = 0.01 mass%).

A precursor Ni_0.34Mn_0.66(OH)₂, Li₂CO₃, and TiO₂ (Li/(Ni+Mn) molar ratio: 1.38) were mixed and sintered in air in two stages: heated to 900°C at 4°C/min and held for 10 h, then cooled to 700°C at 2°C/min and held for 4 h, yielding the base material 0.38Li₂MnO₃·0.62LiNi_0.55Mn_0.45Ti_0.005O₂.

The base material was mixed with a Na-CHA-type aluminosilicate molecular sieve Na₂O·Al₂O₃·35SiO₂ (mass ratio of base material to molecular sieve: 1000 : 2) by mechanical mixing (220 r/min, 25 min), then heat-treated in air (400°C, 5 h) to form a coating layer less than 1 μm thick on the particle surface. XRD analysis confirms the layered structure of the base material is preserved without formation of an impurity phase.

In pouch full cells with graphite negative electrode (4.45–2.5 V), the coated material exhibits a 0.1 C discharge capacity of 227.2 mAh/g, an initial coulombic efficiency of 92.5%, a 0.5 C discharge capacity of 214.4 mAh/g, a capacity retention of 87.2% after 1000 cycles at 1 C, and gas production of 9.24 mL/Ah after 28 days at 60°C, as compared to 217.2 mAh/g, 89.8%, 206 mAh/g, 80.6%, and cell bulging, respectively, for the uncoated base material.

A surface-modified platinum-containing catalyst was developed for proton exchange membrane fuel cells (PEMFC), particularly for high-temperature PEMFCs (HT-PEMFC) operating with phosphoric acid as proton conductor, using poly(melamine-co-formaldehyde) (PMF) as a phosphate-resistant surface-modifying additive to mitigate poisoning of the oxygen reduction reaction (ORR) catalyst by phosphate anions.

An ordered intermetallic L1₀-PtCo/C catalyst was prepared by impregnating commercial Pt/C with cobalt(II) acetylacetonate in chloroform, drying at 70°C, and thermal treatment at 700°C for 12 h (10°C/min ramp) under forming gas (6 vol.% H₂ in Ar), followed by acetic acid washing to remove non-alloyed Co. A Pt shell was formed by acid leaching in acetic acid at 80°C and annealing at 400°C in forming gas (2 h). PMF was applied to the catalyst on a glassy carbon electrode at 20 µg-Pt/cm² loading from a 5 mass% PMF solution in butanol.

Claims specify PMF coverage of 10–40% of the catalyst surface (claim 1), with 22–33% claimed as the optimum range specifically for HT-PEMFCs (claim 12). Four coverage levels were prepared by varying the PMF dose: M1 (~21% coverage, electrochemical surface area (ECSA) retained at 79.0%), M2 (~26%, 73.6%), M3 (~30%, 70.4%), and M4 (~34%, 65.6%), versus an unmodified L1₀-PtCo/C baseline (100% reference).

In 0.1 M HClO₄ — corresponding to LT-PEMFC environments — ORR mass activity peaks at ~130% at M2 (~26%) and collapses to ~67% at M4 (~34%) as excessive PMF blocks reactive sites (Figure). In 0.1 M HClO₄ + 0.1 M H₃PO₄ — corresponding to HT-PEMFC — mass activity instead continues rising to ~200% at M3 (~30%) with specific activity reaching ~300%, and ORR onset potential improves from 951.4 to 963.7 mV (M3, +12.3 mV). The PMF coating is proposed to weaken OH intermediate binding on Pt and to physically block phosphate anion adsorption.

L1₀-PtCo/C: Unmodified ordered intermetallic Pt-Co catalyst on carbon (baseline = 100%)
M1, M2, M3, M4: PMF surface-modified L1₀-PtCo/C at increasing coverage (~21, ~26, ~30, ~34%, respectively)
Figure: ORR mass and specific activity change (%) in 0.1 M HClO₄ vs PMF additive coverage (%)