Anode Material Suppliers
In the following chapters, patent families for which the earliest family member was published after July 24th, 2020
(cutoff date of prior review) are highlighted in red color (a limited number of earlier patents are also highlighted in red,
if they were not included in the prior review).
In maroon color, it is described why - in the author’s opinion - a patent filing could potentially contain
a commercially relevant invention, or why it exhibits a limitation.
Resonac - Japan (links to data sources are included in the full version)
Resonac (http://www.resonac.com, former name: Showa
Denko) is the manufacturer of SCMG artificial graphite active materials, VGCF (vapor grown carbon fiber) conductive additives for the positive
and negative electrode, carbon-coated current collector foils,
and packaging materials for Li-ion batteries.
In 2019, Showa Denko completed the takeover of its bigger rival Hitachi Chemical, in which the Hitachi Group formerly held a
majority stake and subsequently renamed to Resonac. In 2019, Showa Denko made an investment
in Group14 Technologies.
The former Hitachi Chemical division of Resonac is a long-standing, market-leading supplier of anode materials and of other materials
used in Li-ion batteries. A speciality is artificial graphite with carefully tuned pore size distribution for favorable Li-ion diffusion.
In 2018, Showa Denko Materials licensed silicon-based electrolyte technology from US-startup Silatronix to improve electrochemical performance
of its anode materials. In 2018, an investment was made in Massachusetts-based startup company Ionic Materials.
Unique capability (former Hitachi Chemical division): manufacturing of SiOX (0.5 ≤ X ≤ 1) at various performance / cost points
performance materials at comparably high costs - presumably through SiO gas deposition, lower performance materials at comparably low costs -
presumably through SiO milling).
Leap of faith (former Showa Denko division): fast-follower approach in the area of silane coating of carbon will lead to competitive market
Possible composition of future negative electrode materials
Former Hitachi Chemical division (liquid electrolyte cells)
- SiOX (0.5 ≤ X ≤ 1), with highly crystalline SiO2 domains for limited irreversible losses.
- coated with carbon and optionally with a polymer (artificial SEI).
- incorporation of LiF.
- mixed with artificial graphite and flaky graphite.
Former Showa Denko division (semi-solid or solid electrolyte cells)
- Si-coated activated carbon.
- possibly CVD-coated with a carbon layer.
- possibly mixed with artificial graphite and flaky graphite.
Test electrode composition
Former Hitachi Chemical division
- carbon additives: artificial graphite (in-house), Ketjen black (Lion Specialty Chemicals Co., Ltd.), acetylene black (HS-100, Denka), flaky graphite (KS6, IMERYS Graphite & Carbon), carbon black (Super C45, IMERYS Graphite & Carbon).
- binder: CMC/SBR, PAA, PAN, or polyamideimide.
Former Showa Denko division
- carbon additives: VGCF (Resonac), carbon black (IMERYS Graphite & Carbon).
- binder: SBR/CMC.
Figure 25: projected manufacturing process option for Resonac (formerly Hitachi Chemical)
Figure 26: projected manufacturing process option for Resonac (formerly Showa Denko)
News reports and press releases
No news articles were identified in relation to Resonac’s anode materials. The collaboration with Umicore might not have been continued after
the takeover of Hitachi Chemical (latest publication of joint patent family by Umicore and Showa Denko in 2019).
Earlier technical information that remains relevant
The process projection in Figure 25 for Resonac (formerly Hitachi Chemical) retains important steps from the prior review. Consequently,
earlier patent families listed below on SiO gas quenching, carbon CVD or coal tar pitch coating and polymer coating probably remain very
Recently Published Patent Filings
As shown in process Figure 25, recently published patent filings suggest that Resonac (formerly Hitachi Chemical) focuses on process
(and likely cost) optimization while maintaining performance characteristics in SiOX (0.5 ≤ X ≤ 1) materials (key steps: high impact
milling to tune Si & SiO2 domain sizes and crystallinity, incorporation of LiF).
While the incorporation of LiF into SiOX is in focus, the incorporation of LiCl and Al6Si2O13
was also investigated.
Resonac (formerly Showa Denko) made a pivot in its patent filings from with Si nanoparticles and pitch (in collaboration
with Umicore) to a new focus on monosilane CVD coating of activated carbon (process Figure 26), which is being pursued already
by other companies (see Figure 11).
Resonac (formerly Showa Denko) also started efforts towards developing Si-containing active materials that can be combined with
sulfide solid electrolytes.
General patent portfolio characteristics
Among battery materials manufacturers, Resonac holds the 2nd largest number of newly published patent families related to Li-ion
battery anodes since 2018 (117) behind Shanshan. 8 of these patent families are also related to solid-state or semi-solid electrolytes.
Showa Denko made joint filings with Umicore (latest patent family published in 2019) and Nohms Technologies (2 patent filings published
in 2021, related to liquid electrolytes for graphite electrodes, example:
Examples from the patent portfolio - Resonac (formerly Hitachi Chemical)
A) Chemical composition
Process in Figure 25:
Method for manufacturing negative electrode active material for lithium secondary battery, lithium secondary battery,
and negative electrode active material for lithium secondary battery
(2021, covered in patent update): LiF (1 mass%) was mixed with SiO, followed by a heat treatment (900 °C, 3 h, argon
atmosphere). The material was
classified using a 45 μm sieve. Negative electrodes were built in combination with Ketjen black and polyacrylic acid (70 : 15 :
15 mass ratio). As compared to a material without LiF treatment, an improved 1st cycle efficiency of 81% was observed (vs. 63%
when LiF was not used), along with a reversible capacity of 1,300 mAh/g.
This work illustrates very substantial benefits of LiF as additive during SiOX (X ≈ 1) fabrication. LiF probably can be
deployed in a cost-effective manner both from the point of view of raw material sourcing and process costs.
Method for manufacturing negative electrode active material for lithium ion secondary battery, negative electrode active material
for lithium ion secondary battery and lithium ion secondary battery
(2021, covered in patent update): SiO and LiCl (1 : 1 by mass) were heated at 900 °C for 10 h under Ar and electrodes
were produced with Ketjen black, and
polyacrylic acid (PAA, 70 : 15 : 15 by mass, solvent 1-methyl-2-pyrrolidone, NMP). As compared to an SiO sample that was not treated
with LiCl, an improvement of the 1st cycle efficiency was observed (from 63% to 77%).
This work illustrates that 1st cycle losses can be reduced without pre-lithiation with lithium metal reductant, through non-reductive
rearrangements of the SiO structure mediated by LiCl.
Method for manufacturing negative electrode active material for lithium ion secondary battery,
negative electrode active material for lithium ion secondary battery and lithium ion secondary battery
(2020, covered in patent update): SiO and AlF3 were mixed (1 : 0.6 molar ratio) and heat treated at up to 950 °C under argon, resulting in a powder
that consists of an Si and an Al6Si2O13 phase. Electrodes were built with this powder in combination
with Ketjen black and PAA binder
(70 : 15 : 15 by mass), which exhibit more favorable 1st cycle coulombic efficiency (up to 80%) as compared to SiO-based electrodes
(up to 66%).
This work illustrates how the 1st cycle coulombic efficiency can be improved by partially converting SiO to
Al6Si2O13. It might
be possible to also improve other electrochemical characteristics with this approach, such as cycling stability. Cost savings
might be possible as compared to electrochemical pre-lithiation procedures and/or the invention could be combined with pre-lithiation
for potentially synergistic effects.
Process in Figure 25:
Lithium ion secondary battery negative electrode material, lithium ion secondary battery, and method for
producing negative electrode material for lithium ion secondary battery
(2020, covered in patent update): the Coulombic efficiency of SiOX (X ≈ 1) was improved by forming crystalline
domains (see Figure 27) that exhibit limited irreversible lithium absorption. This was achieved by mixing LiF with SiO (1 :
1 molar ratio), followed by calcination at up to 900 °C.
This work could allow for reduced irreversible losses and parasitic reactions in SiOX (X ≈ 1) active materials, which
could in turn allow for higher energy electrodes with increased SiOX content.
Figure 27: X-ray diffraction measurement of SiOX (X ≈ 1) material with highly crystalline SiO2 domains (Resonac,
formerly Hitachi Chemical)
B) Particle nano- & microarchitectures, composites
C) Surfaces & coatings
D) Large scale manufacturing, reliability
E) Negative electrode formulations (for liquid electrolytes)
Examples from the patent portfolio - Resonac (formerly Showa Denko)
B) Particle nano- & microarchitectures, composites
C) Surfaces & coatings
Process in Figure 26:
Carbon-coated composites and their uses
(2021, covered in patent update): activated carbon (BET SSA: 900 m2/g) was treated with silane gas in a
tube furnace (1.3 volume% in nitrogen, 500 °C, 760 torr, 6 h). The resulting composite particles exhibit a silicon
content of 45 mass% and a BET specific surface area of 16.9 m2/g. The material exhibits a reversible capacity of 1,800
mAh/g and a first cycle efficiency of 91.2%. Electrolyte: EC / EMC / DEC = 3 : 5: 2 by volume, additives: VC (1 mass%),
FEC (10 mass%). In full cells with LCO-based positive electrodes, 60% capacity retention was observed after 50 cycles.
While a favorable 1st cycle efficiency was obtained, further work appears to be necessary to improve cycling stability in full cells.
TITANIUM OXIDE-SILICON COMPOSITE AND USE OF SAME
(2021, covered in patent update): TiO2 was exposed to a He atmosphere, followed by treatment with silane gas (400 °C), followed by purging with He gas.
An SEM-EDX analysis exhibits that Si was incorporated between TiO2 domains. Negative electrode formulation: Ti-Si-O material,
graphite, VGCF (Resonac), carbon black, CMC (CMC1300 from Daicel), SBR (10.1 : 79.9 : 3 : 2 : 2.5 : 2.5 by mass). In half cells,
a discharge capacity of 494 mAh/g was observed and a 1st cycle efficiency of 89.3%.
This work could allow for negative electrode active materials with favorable longevity,
if the material exhibits reduced parasitic reactivity as compared to SiOX (X ≈ 1).
F) Negative electrode active materials & formulations for solid-state or semi-solid Li-ion batteries
COMPOSITE MATERIAL, MANUFACTURING METHOD THEREFOR, NEGATIVE ELECTRODE MATERIAL FOR LITHIUM ION SECONDARY BATTERY, AND THE LIKE
(2021, covered in patent update): this patent describes efforts towards making titanium oxide coated anode materials
that can be used in combination with sulfide solid electrolytes. SCMG artificial graphite and an Si-carbon material were combined
with titanium oxide and dry-mixed (VM-10 mixer, Dalton Corp.), followed by a heat treatment (1,100 °C with SCMG precursor, 700 °C
with Si-carbon precursor, 1 h, nitrogen atmosphere). This material was further treated with an MP-01 mini (Paulec Co.) apparatus
to obtain a titanium oxide coating, followed by another heat treatment (400 °C, air, ≤25% humidity). The coating leads to improved
This work illustrates how Resonac employs a titanium oxide coating to graphite and Si-carbon materials to improve longevity in
cells with sulfide solid electrolytes.
ALL-SOLID LITHIUM ION BATTERY NEGATIVE ELECTRODE MIXTURE AND ALL-SOLID LITHIUM ION BATTERY
(2020): Si particles (50 nm average diameter, 51.5 m2/g BET SSA) and petroleum pitch (10 : 11.54 mass ratio) were mixed
at 250 °C at high shear rate under inert gas, followed by a heat treatment (up to 1,100 °C, under nitrogen). With the resulting
material, negative electrodes were prepared in combination with 3 mass% Super C45 carbon black (IMERYS Graphite & Carbon) and 3
mass% polyacrylate binder. Solid-state battery cells were prepared with Li2S ∙ P2S5 and an
LCO-based positive electrodes.
This work illustrates how Resonac is optimizing its negative electrode active materials for use with sulfide electrolytes.