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Lithium-ion batteries – electrolytes – solid & semi-solid
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A crosslinkable PEO polymer with allyl groups (-CH2-O-CH2-CH=CH2)
and a non-crosslinkable PEO
polymer were blended at various ratios (between
5:5 and 9:1, i.e. larger ratio of crosslinkable PEO) to form an optimized network structure.
The polymer mixture was combined with LiTFSI (lithium bis(trifluoromethanesulphonyl)imide),
LSTP (Li-Si-Ti-phosphate) ceramic, and a crosslinking agent
(trimethylolpropane trimethacrylate) in acetonitrile solvent. The solution was stirred with a magnetic bar for
24 h at room temperature. The resulting mixture was then cast onto a substrate, dried at room temperature for 12 h,
followed by vacuum drying (100°C, 12 h) to form a 200 μm thick electrolyte film. The film was
subsequently exposed to ethylmethyl carbonate (EMC) vapor for 72 h, resulting in EMC being
incorporated at ≈1.2-6 mass%.
This electrolyte film exhibits an ionic conductivity of 1.7 × 10-3 S/cm at 25°C
and 3.1 × 10-3 S/cm at 50°C.
As shown in the Figure below, samples with optimized crosslinkable / non-crosslinkable polymer ratios and vapor-deposited EMC
(red dots, examples 1-3, 실시예1-3) demonstrate ionic conductivities approximately one order of
magnitude higher than comparative examples (black dots, comparative examples 4-9, 비교예4-9) that lack
vapor-deposited polar compounds. The samples in the pink-shaded area (with excessive
non-crosslinkable polymer content) could not be properly measured as their crosslinked
structure collapsed (datapoints 비교예2-3 are therefore extrapolated rather than measured).
This work illustrates promising ionic conductivities for semi-solid composite electrolytes with crosslinked / non-crosslinked PEO,
ceramic LSTP, and a minor amount of EMC.
For LSTP, LiSiO2TiO2(PO4)3 as stated in the patent is not a balanced formula.
Presumably, a subscript after Li was inadvertently omitted and the formula is: Li9SiO2TiO2(PO4)3.
LSTP is based on comparably abundant elements.
It would be interesting to know if the replacement of EMC with a higher-boiling
liquid (improved inherent safety characteristics) is possible without significantly decreased ionic conductivity.
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Lithium-ion batteries – negative electrode (excluding Li metal electrodes)
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A Si-carbon composite active material (D50: ≈5 μm) was coated with a layer containing
cyclized polyacrylonitrile (PAN) and LLTO nanoparticles (e.g. Li0.5La0.5TiO3).
The Si-carbon composite material was obtained through chemical vapor deposition (CVD) of monosilane
on carbon.
The Si-carbon material and PAN (2.5 mass%) were dispersed in N,N-dimethylformamide (DMF) and
heated (80°C, continuous stirring). After PAN was completely dissolved,
nano-LLTO (1 mass%) was added and thoroughly dispersed to form a mixed slurry.
The slurry temperature was raised (100°C, continuous stirring) until the organic
solvent completely evaporated. The resulting powder was ground and heat-treated in a box
furnace (320°C, 1 h, argon atmosphere) to cyclize PAN.
The resulting material exhibits a coating thickness
of ≈100 nm.
In half-cells with Li6PS5Cl solid electrolyte, the material
exhibits a first cycle discharge capacity of 2,037 mAh/g and a capacity retention of
88.7% after 50 cycles (0.1 C charge / discharge), compared to 1,470 mAh/g and 66.3% for a comparative material
(coated only with LLTO, without PAN).
This work illustrates how a cyclized PAN / nano-LLTO result substantially improve electrochemical
characteristics in cells with sulfide solid electrolyte.
Given that LLTO may undergo redox reactions at 0 V vs. Li+/Li
(academic reference, although such reactions might be
slowed down or fully prevented if LLTO is completely surrounded by cyclized PAN), the explanation
for improved performance might or might not involve a complex interface reaction sequence.
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Lithium-ion batteries – positive electrode
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A high-nickel positive electrode material with cobalt-boron-antimony multi-element
composite coating was prepared. The material includes a high-nickel core and a Co-B-Sb
composite coating layer on the surface.
The precursor Ni0.95Co0.04Mn0.01(OH)2 was mixed with
LiOH·H2O and dopants (SrO, Nb2O5, and CaCO3) at a
molar ratio of Li : metals = 1.06 : 1, followed by heat treatment (525°C, 2 h,
then 750°C, 12 h, oxygen atmosphere) to obtain
LiNi0.9468Co0.04Mn0.01Sr0.00089Nb0.00084Ca0.00147O2.
This material was mixed with CoOOH (3,000 ppm), followed by a heat treatment (625°C,
9 h, oxygen atmosphere). The resulting cobalt-coated high-nickel material was then
ball-milled (300 rpm, 1.5 h) with Sb2O3 (1,000 ppm) and
H3BO3 (500 ppm) to obtain the multi-element composite coated
material. An SEM image (see Figure) illustrates a smooth composite coating
layer.
In half-cells, the material exhibits a discharge capacity of 224.2 mAh/g and a
first cycle efficiency of 90.2%. At 2 C discharge, it delivers 93.5% of its low-rate
capacity. After 50 cycles at 45°C, the capacity retention is 94.7% with a direct
current resistance (DCR) increase of 20.3%, as compared to 220.1 mAh/g, 89.0%,
90.4%, 91.3%, and 46.9% for a comparative material prepared by directly coating the
material with Co, B, and Sb in a single step without ball milling.
This work illustrates how well-balanced performance with high-Ni (95%) NMC can be achieved through doping with Sr, Nb and Ca, and a 2-layer coating
(layer 1 facing core: Co-enriched, layer 2 facing electrolyte: Sb / B-based).
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Fuel cells (PEMFC / SOFC / PAFC / AEMFC) – electrochemically active materials
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A platinum catalyst for fuel cells was prepared using electron beam irradiation for metal
reduction instead of chemical reducing agents.
A carbon support was dispersed in a water/ethanol mixed solvent. A conducting
polymer (e.g. polypyrrole) precursor was added to the dispersion along with a surfactant. This mixture
was subjected to low-power electron beam irradiation (0.01-0.05 MeV, 0.1-5 mA) to coat
the carbon support with the polymer.
The polymer-coated carbon support was then mixed with a platinum precursor (e.g. platinum
acetylacetonate) and surfactant (e.g. oleylamine).
The pH was adjusted to 5-8 with NaOH (1 M). This mixture was subjected to high-power
electron beam irradiation (0.01-2 MeV, 0.1-20 mA) to reduce the platinum ions and deposit
metal nanoparticles on the carbon support. The resulting catalyst was filtered and dried
(70°C).
Various catalysts were prepared with different polymer content: 0 mass% (comparative
example 1), 3 mass% (example 1), 5 mass% (example 2), 10 mass% (comparative example 2),
and 20 mass% (comparative example 3). TEM analysis (see top Figure) exhibits uniform platinum
nanoparticles with an average size of ≈2.5 nm for all samples, confirming successful
platinum deposition regardless of polymer content.
Membrane electrode assemblies (MEAs) were fabricated using the prepared catalysts on the
cathode side (0.4 mg-Pt/cm2) and commercial Pt/C on the anode side
(0.2 mg-Pt/cm2), with Nafion 211 as the membrane. Performance tests were
conducted under both high humidity (see bottom Figure, a), 70°C, 100% RH, 0 Bar) and low humidity (see bottom Figure, b), 80°C, 40% RH,
1.5 Bar) conditions.
While no significant performance differences were observed under high humidity conditions,
the catalyst with 3 mass% polymer coating (example 1) exhibited superior performance under
low humidity conditions compared to both the uncoated catalyst (comparative example 1) and
the 10 mass% polymer-coated catalyst (comparative example 2). This demonstrates improved
water management in the catalyst layer due to the optimized hydrophilic coating.
This work illustrates how electron beam irradiation can be used to both obtain a tailored carbon support surface and reduced, well-distributed
Pt nanoparticles, resulting in favorable PEMFC catalyst performance at 40% relative humidity.
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The premium version includes another two patent discussions, plus an Excel list with 50-100 commercially relevant recent patent families.
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Triweekly patent lists for other categories (Excel files are included for premium users)
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- Lithium metal batteries (excluding Li-S, Li-Air): XLSX
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- Lithium-air batteries: XLSX
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- Lithium-ion batteries – electrolytes – liquid: XLSX
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- Lithium-ion batteries – separators: XLSX
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- Lithium-sulfur batteries: XLSX
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- Na-ion batteries: XLSX
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Prior patent updates
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2025-04-08
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2025-03-18
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2025-02-25
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2025-02-04
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2025-01-14
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