Battery electrolyte
By employing a double-layer solid electrolyte separator and a specific electrolyte combination in solid-state batteries, the problem of poor electrochemical stability of solid-state batteries under high-voltage cathodes is solved, achieving high-efficiency electrochemical performance and improved durability.
Patent Information
- Application Number
- CN202511265169.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2024-09-10
- Filing Date
- 2025-09-05
- Publication Date
- 2026-03-17
AI Technical Summary
Existing solid-state batteries have limited applications when used with high-voltage cathodes due to poor electrochemical stability, especially the stability issues of lithium-ion/lithium at voltages above 3.0 volts, which have not been effectively resolved.
A dual-layer solid electrolyte separator is adopted, including a sulfide-type solid electrolyte and a chloride-type solid electrolyte, which are used as the anode and cathode, respectively, namely Li6PS5X and Li2.5-yZrCl5.5-yO0.5. Combined with a silicon-based anode and a high-nickel cobalt-manganese cathode, the electrochemical stability is improved by the design of the dual-layer solid electrolyte separator.
This achievement ensures the stability of the high-voltage cathode under high oxidation voltage, improves the electrochemical performance and long-term durability of solid-state batteries, and promotes efficient ion transport and extended cycle life.
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Figure CN121688080A_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to electrolytes for lithium - ion batteries. Background Art
[0002] Solid - state batteries have high energy density, but require high - performance solid - state electrolytes, cathodes, and anodes. However, their poor electrochemical stability above 3.0 volts (V) compared to lithium ions / lithium limits their use with high - voltage cathodes. Summary of the Invention
[0003] A solid - state battery cell includes: a silicon - based anode having a sulfide anode electrolyte; a nickel - cobalt - manganese cathode having an oxychloride cathode electrolyte; and a double - layer solid - state electrolyte separator located between the anode and the cathode and in direct contact with the anode and the cathode, having a first layer of sulfide - type solid - state electrolyte adjacent to the anode and a second layer of oxychloride - type solid - state electrolyte adjacent to the cathode. The sulfide - type solid - state electrolyte in the anode and the first layer of the separator can be argyrodite with the chemical formula Li6PS5X, where X is Cl or Br. The oxychloride - type solid - state electrolyte in the cathode and the second layer of the separator can be Li ,
[0004] ZrCl 5.5-y O 0.5 , where 0 < y ≤ 1.0. The silicon particles in the silicon - based anode can be selected from the group consisting of: silicon nanoparticles; silicon microparticles; SiO x nanoparticles, where 0 < x < 2; SiO x microparticles, where 0 < x < 2; and silicon - carbon composites. The nickel - cobalt - manganese in the cathode can be LiNi x Co y Mn 1-x-y O2, where x > 0.7. The nickel - cobalt - manganese can be NCM811. At least one of the anode and the cathode can further include a carbon additive. At least one of the anode and the cathode can further include a polymer binder. At least one layer of the double - layer solid - state electrolyte separator can further include a polymer binder.
[0004] A method of manufacturing a solid - state battery cell includes: forming an anode by combining a silicon active material with a sulfide - type solid - state electrolyte; forming a cathode by combining high - nickel nickel - cobalt - manganese with an oxychloride - type solid - state electrolyte; forming a double - layer solid - state electrolyte separator by depositing a first layer of sulfide - type solid - state electrolyte and depositing a second layer of oxychloride - type solid - state electrolyte on the first layer; and assembling the anode, the cathode, and the double - layer solid - state electrolyte separator such that the first layer of the separator is adjacent to the anode and the second layer of the separator is adjacent to the cathode. The sulfide - type solid - state electrolyte can be argyrodite with the chemical formula Li6PS5X, where X is Cl or Br. The oxychloride - type solid - state electrolyte can be Li2.5-y ZrCl 5.5-y O 0.5 where 0 < y ≤ 1.0. In some configurations, the method further includes adding a carbon additive to at least one of the anode and the cathode. In other configurations, the method further includes adding a polymer binder to at least one of the anode, the cathode, and the dual-layer solid-state electrolyte separator.
[0005] A solid-state battery system includes: an anode composite of silicon active material and a sulfide solid electrolyte, a cathode composite of nickel cobalt manganese and a spinel-structured oxide solid electrolyte, and a dual electrolyte solid separator located between and in direct contact with the anode and the cathode, the separator having a first layer of sulfide solid electrolyte adjacent to the anode and a second layer of spinel-structured oxide solid electrolyte adjacent to the cathode. The sulfide solid electrolyte in the anode and the first layer of the separator can be Li6PS5X, where X is Cl or Br, and the spinel-structured oxide solid electrolyte in the cathode and the second layer of the separator is Li 2.5-y ZrCl 5.5-y O 0.5 where 0 < y ≤ 1.0. The silicon active material in the anode can be selected from the group consisting of: silicon nanoparticles; silicon microparticles; SiO x nanoparticles, where 0 < x < 2; SiO x microparticles, where 0 < x < 2; and silicon-carbon composites, and the chemical formula of nickel cobalt manganese in the cathode is LiNi x Co y Mn 1-x-y O2, where x > 0.7. The nickel cobalt manganese can be NCM811. At least one of the anode and the cathode can include a carbon additive. At least one layer of the dual electrolyte solid separator can include a polymer binder. BRIEF DESCRIPTION OF THE DRAWINGS
[0006] Figure 1 is a schematic diagram of a solid-state battery;
[0007] Figure 2 is a graph of electrolyte current density versus potential;
[0008] Figure 3 is a graph of electrolyte voltage versus potential;
[0009] Figure 4 is a graph of electrolyte capacity versus number of cycles; and [[ID=4N]]
[0010] Figure 5 is a flowchart of a method of forming a Figure 1 solid-state battery. DETAILED DESCRIPTION
[0011] As needed, detailed embodiments of the claimed subject matter are disclosed herein; however, it is to be understood that the disclosed embodiments are merely representative and may be embodied in various and alternative forms. The figures are not necessarily drawn to scale; some features may be enlarged or minimized to show details of particular components. Thus, the specific structural and functional details disclosed herein (such as the composition of a silicon-based anode with a sulfide anode electrolyte, a nickel-cobalt-manganese cathode with a chloro-oxide cathode electrolyte, and a bilayer solid electrolyte separator) should not be construed as limiting, but rather as a representative basis for teaching one skilled in the art to employ embodiments of the claimed subject matter in various ways in solid-state battery technology.
[0012] Unless otherwise expressly stated, all numerical values and ranges associated with quantities, measurements, percentages, weights, and similar numerical references within this document should be understood to be preceded by the term "about". This applies even when the term "about" is not explicitly used. It is intended that all values and ranges encompass variations that may be caused by standard measurements, manufacturing processes, material properties, and the intended functionality of various aspects of the present disclosure. For example, when a chloro-oxide type solid electrolyte is described as having a chemical formula of "Li 2.5- y ZrCl 5.5-y O 0.5 ", it should be understood as "about Li 2.5-y ZrCl 5.5-y O 0.5 ". Additionally, when numerical values are presented as ranges, such as "x > 0.7" in the chemical formula of a nickel-cobalt-manganese cathode LiNi x Co y Mn 1-x-y O2, the range should be interpreted as effectively meaning "about x > 0.7". Similarly, when silicon oxide particles are described as "SiO x , where 0 < x < 2", it should be understood as "SiO x , where about 0 < x < about 2". Such variations are implicitly incorporated within the scope of the present disclosure, including all compositions, structures, and methods described in the appended claims.
[0013] The combination of a silicon anode and a high-nickel layered cathode provides attractive chemistry for high-energy solid-state batteries. However, due to low oxidation stability, current electrolytes may react unfavorably with the high-nickel cathode.
[0014] The present disclosure relates to solid-state battery configurations and methods for their manufacture. The presented solid-state battery utilizes a dual solid-state electrolyte system that combines the advantages of lithium phosphorus sulfur chloride (LPSC) electrolyte and lithium zirconium oxychloride (LZCO) electrolyte to form a high-performance energy storage solution. This arrangement involves the strategic use of two different solid-state electrolytes, where LZCO serves as the cathode electrolyte and LPSC is used as the anode electrolyte. This dual electrolyte approach is implemented through a bilayer solid-state electrolyte separator that is specifically configured to complement the respective cathode and anode electrolyte materials. The LZCO cathode electrolyte is a specially synthesized oxychloride solid-state electrolyte that exhibits stability at high oxidation voltages up to 4.2V. This property makes it particularly suitable for use with high-voltage cathode materials, thus addressing the limitations of many existing solid-state electrolytes.
[0015] On the anode side, LPSC electrolyte is utilized due to its high stability towards reduction voltages, making it an ideal choice for pairing with silicon anodes. This combination allows for the utilization of the high theoretical capacity of silicon while alleviating the stability issues often encountered in solid-state battery designs.
[0016] The composite anode in this battery system consists of two main components: a silicon-based (Si-based) active material and the LPSC anode electrolyte. The Si active material can take various forms, including pure Si nanoparticles and microparticles, Si oxide (SiO x , where 0 < x < 2) nanoparticles and microparticles, or Si-carbon (Si-C) composites. To improve the performance of the electrode, a small amount of C additives (such as carbon black and polymer binders) can be incorporated to enhance conductivity and mechanical integrity, respectively.
[0017] The proposed cathode structure is a composite similar to that of the anode. The chemical formula of high-nickel cobalt manganese (NCM) (such as NCM811) is LiNi x Co y Mn 1-x-y O2, where (x > 0.7, such as NCM811) is the active material, and the aforementioned LZCO is the cathode electrolyte. Similar to the anode, C additives (such as carbon black) and polymer binders can be included to increase conductivity and structural stability.
[0018] The bilayer solid-state electrolyte separator includes an LPSC layer corresponding to the anode electrolyte composition and an LZCO layer corresponding to the cathode electrolyte. The use of a small amount of polymer binder in each layer increases the mechanical strength and integrity of the separator structure. Specifically, the chemical formula of the LZCO electrolyte can be Li 2.5-y ZrCl 5.5-y O 0.5 , where 0 < y ≤ 1.0. The cathode electrolyte can have the composition Li1.75 ZrCl 4.75 O 0.5 。The LPSC electrolyte can be a lithium thiophosphate garnet with the chemical formula Li6PS5X, where X is Cl or Br.
[0019] This dual solid electrolyte system enables the use of a high-capacity Si anode and a high-voltage cathode without an active material coating. The stability of the LZCO cathode electrolyte at high oxidation voltages improves the electrochemical performance and long-term durability of solid-state batteries in which the LZCO cathode electrolyte can be incorporated. The high ionic conductivity of both the LPSC and LZCO components promotes efficient ion transport throughout the solid-state battery structure.
[0020] In addition, the mechanical properties of LPSC, particularly its low elastic modulus and ductility, can help maintain contact between the Si anode and the electrolyte during cycling, thus contributing to an extended cycle life. Composite electrodes and bilayer electrolyte separators can be fabricated using established large-scale production methods.
[0021] Figure 1 is a schematic diagram of a solid-state battery cell 10. An anode 12, which can be a Si-based anode composite, incorporates Si particles. The Si particles can be in the form of nanoparticles, microparticles, SiOx particles (where 0 < x < 2), or Si-C composites. The anode also contains a sulfide anode electrolyte, which specifically can be a lithium thiophosphate garnet-type solid electrolyte with the chemical formula Li6PS5X, where X is Cl or Br. A bilayer solid electrolyte separator 14 is layered with the anode 12. The bilayer solid electrolyte separator 14 is in direct contact with both the anode 12 and the cathode 16. The top layer of the separator 18 includes a sulfide-type solid electrolyte that corresponds to the composition of the anode electrolyte with the chemical formula Li6PS5X in the anode 12. The top layer of the separator 18 is adjacent to and in direct contact with the anode 12. The bottom layer of the separator 20 is a chloro-oxide-type solid electrolyte, specifically Li 2.5- y ZrCl 5.5-y O 0.5 。The bottom layer of the separator 20 is positioned adjacent to and in direct contact with the cathode 16. The cathode 16 can be a composite of NCM active material and a chloro-oxide cathode electrolyte. The chemical formula of NCM can be LiNi x Co y Mn 1-x-yO2, where x > 0.7, and NCM811 is a specific example used in the solid-state battery cell 10. Both the anode 12 and the cathode 16 may include additional components such as C additives for improving conductivity and polymer binders for improving structural integrity. The C additives may be additives such as carbon black, graphene, C nanotubes, or acetylene black. The polymer binders may be materials such as polyvinylidene fluoride, carboxymethyl cellulose, styrene-butadiene rubber, or polyethylene oxide. Similarly, the layers of the bilayer solid-state electrolyte separator 14 may also incorporate polymer binders to increase mechanical properties.
[0022] Figure 2 This is a graph showing the electrochemical stability windows of LZCO and LPSC. The graph plots the current density (μA / cm²) for LZCO and LPSC. 2 The potential (V versus Li+ / Li) is used. The potential ranges from 0 to 5.0 V, while the current density axis ranges from -100 μA / cm. 2 Extended to 100 μA / cm 2 The LPSC curves show a sharp increase in cathode current below 1.3V, indicating its reduction potential, and remain relatively stable up to 2.8V. Above 2.8V, the anode current increases significantly, indicating oxidation. In contrast, the LZCO curves show a reduction potential at 1.6V and remain stable up to 4.2V before showing signs of oxidation. These stability windows are clearly marked on the graphs for LPSC from 1.3V to 2.8V and for LZCO from 1.6V to 4.2V. This graph highlights the excellent oxidation stability of LZCO, making it particularly suitable as a high-voltage cathode material, while the lower reduction potential of LPSC indicates better compatibility with low-voltage anode materials.
[0023] Figure 3 The formation cycle characteristics of LPSC and LZCO at a charge rate of 0.1 coulombs (C) are shown. The graphs plot V versus capacity (mAh) for LPSC and LZCO. The x-axis represents capacity and ranges from 0 to 4.0 mAh, while the y-axis shows V spanning from 2.0 to 4.5 V. The LPSC curve shows an increasing V distribution, which starts at approximately 3.2 V and steadily rises to approximately 4.2 V as the capacity increases to 4.0 mAh. This upward trend indicates consistent charging behavior of LPSC. In contrast, the LZCO curve shows a decreasing voltage distribution, which starts at approximately 4.2 V as the capacity reaches 3.7 mAh and decreases to approximately 2.5 V.
[0024] Figure 4The rate performance of an all-cell solid-state battery consisting of an NMC811 cathode, an LZCO-LPSC dual electrolyte, and a Si anode is shown. The graphs plot capacity and efficiency (%) versus cycle life in mAh / g for performance at various C-rates from C / 10 to 2C. The parameters tracked are charge capacity, discharge capacity, and efficiency. The cell exhibits high initial capacity at C / 10, with a charge capacity reaching approximately 180 mAh / g and efficiency rapidly increasing to near 100%. As the C-rate increases, a gradual decrease in capacity is observed, with the discharge capacity dropping from approximately 160 mAh / g at C / 5 to approximately 140 mAh / g at C / 2, and further to approximately 120 mAh / g at 1C. Notably, the cell maintains high efficiency at all these rates. At 2C, the capacity drops more significantly to approximately 100 mAh / g, while the efficiency decreases to approximately 70%. Data shows that this NMC811 / LZCO-LPSC / Si configuration exhibits high rate capability, especially at medium C rates, indicating its potential for high-performance solid-state battery applications.
[0025] Figure 5 This is a flowchart of a method for manufacturing a solid-state battery cell 22. Step 24 includes combining a silicon active material with a sulfide-type solid electrolyte. The sulfide-type solid electrolyte can be a silver-germanium sulfide mineral with the chemical formula Li6PS5X, where X is Cl or Br. Step 26 is forming a cathode, which combines an NCM material with an oxychloride-type solid electrolyte. The oxychloride-type solid electrolyte can have a composition Li 2.5-y ZrCl 5.5-y O 0.5 Step 28 is the formation of a double-layer solid electrolyte separator, which is a two-part process: first, a first sulfide-type solid electrolyte layer is deposited, and then a second oxychloride-type solid electrolyte layer is deposited on top of the first layer. Step 30 is the assembly of the solid-state battery cell 10, wherein the anode, cathode, and double-layer solid electrolyte separator are assembled such that the first sulfide-type layer of the separator is adjacent to the anode, and the second oxychloride-type layer is adjacent to the cathode.
[0026] While representative embodiments have been described above, these embodiments are not intended to describe all possible forms of the invention. The wording used in this specification is descriptive rather than limiting, and it should be understood that various changes may be made without departing from the claimed subject matter. Furthermore, features of various embodiments may be combined to form other embodiments not explicitly described or shown, but within the scope of the claimed subject matter.
[0027] According to the present invention, a solid-state battery cell is provided, the solid-state battery cell having: a silicon-based anode having a sulfide anode electrolyte; a nickel cobalt manganese cathode having a chloro-oxide cathode electrolyte; and a double-layer solid electrolyte separator located between the anode and the cathode and in direct contact with the anode and the cathode, having a first layer of sulfide-type solid electrolyte adjacent to the anode and a second layer of chloro-oxide-type solid electrolyte adjacent to the cathode.
[0028] According to an embodiment, the sulfide-type solid electrolyte in the anode and the first layer of the double-layer solid electrolyte separator is argyrodite of the chemical formula Li6PS5X, where X is Cl or Br.
[0029] According to an embodiment, the chloro-oxide-type solid electrolyte in the cathode and the second layer of the double-layer solid electrolyte separator is Li 2.5-y ZrCl 5.5-y O 0.5 , where 0 < y ≤ 1.0.
[0030] According to an embodiment, the silicon particles in the silicon-based anode are selected from the group consisting of: silicon nanoparticles; silicon microparticles; SiO x nanoparticles, where 0 < x < 2; SiO x microparticles, where 0 < x < 2; and silicon-carbon composites.
[0031] According to an embodiment, the nickel cobalt manganese in the cathode is LiNi x Co y Mn 1-x-y O2, where x > 0.7.
[0032] According to an embodiment, the nickel cobalt manganese is NCM811.
[0033] According to an embodiment, at least one of the anode and the cathode further includes a carbon additive.
[0034] According to an embodiment, at least one of the anode and the cathode further includes a polymer binder.
[0035] According to an embodiment, at least one layer of the double-layer solid electrolyte separator further includes a polymer binder.
[0036] According to the present invention, a method of manufacturing a solid-state battery cell includes: forming an anode by combining a silicon active material with a sulfide-based solid electrolyte; forming a cathode by combining high-nickel nickel cobalt manganese with an oxychloride-based solid electrolyte; forming a double-layer solid electrolyte separator by depositing a first layer of sulfide-based solid electrolyte and depositing a second layer of oxychloride-based solid electrolyte on the first layer; and assembling the anode, cathode, and double-layer solid electrolyte separator such that the first layer of the separator is adjacent to the anode and the second layer of the separator is adjacent to the cathode.
[0037] In one aspect of the present invention, the sulfide-based solid electrolyte is argyrodite having the chemical formula Li6PS5X, where X is Cl or Br.
[0038] In one aspect of the present invention, the oxychloride-based solid electrolyte is Li 2.5-y ZrCl 5.5-y O 0.5 , where 0 < y ≤ 1.0.
[0039] In one aspect of the present invention, the method includes adding a carbon additive to at least one of the anode and the cathode.
[0040] In one aspect of the present invention, the method includes adding a polymer binder to at least one of the anode, the cathode, and the double-layer solid electrolyte separator.
[0041] According to the present invention, there is provided a solid-state battery system having: an anode composite of a silicon active material and a sulfide-based solid electrolyte of the argyrodite type; a cathode composite of nickel cobalt manganese and a spinel-structured oxide solid electrolyte; and a bi-electrolyte solid separator located between the anode and the cathode and in direct contact with the anode and the cathode, the separator having a first layer of sulfide-based solid electrolyte of the argyrodite type adjacent to the anode and a second layer of spinel-structured oxide solid electrolyte adjacent to the cathode.
[0042] According to an embodiment, the sulfide-based solid electrolyte in the anode and the first layer of the separator is Li6PS5X, where X is Cl or Br, and the spinel-structured oxide solid electrolyte in the cathode and the second layer of the separator is Li 2.5- y ZrCl 5.5-y O 0.5 .
[0043] According to an embodiment, the silicon active material in the anode is selected from the group consisting of: silicon nanoparticles; silicon microparticles; SiOx nanoparticles, where 0 < x < 2; SiO x microparticles, where 0 < x < 2; and silicon-carbon composites, and the chemical formula of the nickel cobalt manganese in the cathode is LiNi x Co yMn 1-x-y O2, where x>0.7.
[0044] According to the example, the nickel-cobalt-manganese alloy is NCM811.
[0045] According to an embodiment, at least one of the anode and cathode includes a carbon additive.
[0046] According to an embodiment, at least one layer of the dual-electrolyte solid separator includes a polymer binder.
Claims
1. A solid-state battery cell, comprising: a silicon-based anode having a sulfide anolyte; a nickel cobalt manganese cathode having a oxychloride catholyte; and a dual-layer solid-state electrolyte separator between and in direct contact with the anode and the cathode having a first layer of sulfide-type solid-state electrolyte adjacent to the anode and a second layer of oxychloride-type solid-state electrolyte adjacent to the cathode.
2. The solid-state battery cell of claim 1, wherein the sulfide-type solid-state electrolyte in the anode and the first layer of the dual-layer solid-state electrolyte separator is argyrodite of the formula Li6PS5X, where X is CI or Br.
6. The solid-state battery cell of claim 5, wherein the nickel cobalt manganese is NCM811.
3. The solid-state battery cell of claim 1, wherein the oxychloride-type solid-state electrolyte in the second layer of the bi-layer solid-state electrolyte separator and the cathode is Li 2.5-y ZrCl 5.5-y O 0.5 .
4. The solid-state battery cell of claim 1, wherein the silicon particles in the silicon-based anode are selected from the group consisting of: silicon nanoparticles; silicon microparticles; SiO x nanoparticles, where 0 < x < 2; SiO x microparticles, where 0 < x < 2; and silicon-carbon composites.
5. The solid-state battery cell of claim 1, wherein the nickel cobalt manganese in the cathode is LiNi x Co y Mn 1-x-y O2, wherein x > 0.
7.
7. The solid-state battery cell of claim 1, wherein at least one of the anode and the cathode further comprises a carbon additive.
8. The solid-state battery cell of claim 1, wherein at least one of the anode and the cathode further comprises a polymeric binder.
9. The solid-state battery cell of claim 1, wherein at least one layer of the dual-layer solid-state electrolyte separator further comprises a polymeric binder.
10. A method of manufacturing a solid-state battery cell, the method comprising: forming an anode by combining a silicon active material with a sulfide-type solid-state electrolyte; forming a cathode by combining a high nickel nickel cobalt manganese with an oxychloride-type solid-state electrolyte; forming a dual-layer solid-state electrolyte separator by depositing a first layer of sulfide-type solid-state electrolyte and a second layer of oxychloride-type solid-state electrolyte on the first layer; and assembling the anode, the cathode, and the dual-layer solid-state electrolyte separator such that the first layer of the separator is adjacent to the anode and the second layer of the separator is adjacent to the cathode.
11. A solid-state battery system, comprising: an anode composite of a silicon active material and an argyrodite solid-state electrolyte; a cathode composite of a nickel cobalt manganese and a spinel-structured oxide solid-state electrolyte; and a dual-electrolyte solid-state separator between and in direct contact with the anode and the cathode, the separator having a first layer of sulfide-type solid-state electrolyte adjacent to the anode and a second layer of spinel-structured oxide solid-state electrolyte adjacent to the cathode.
14. The solid-state battery system of claim 13, wherein the nickel cobalt manganese is NCM811.
15. The solid-state battery system of claim 11, wherein at least one of the anode and the cathode comprises a carbon additive, and wherein at least one layer of the dual-electrolyte solid-state separator comprises a polymeric binder. 12. The solid-state battery system of claim 11, wherein the argyrodite-type solid-state electrolyte in the first layer of the anode and the separator is Li6PS5X, where X is CI or Br, and the spinel-structured oxide solid-state electrolyte in the second layer of the cathode and the separator is Li 2.5-y ZrCl 5.5-y O 0.5 .
13. The solid-state battery system of claim 11, wherein the silicon active material in the anode is selected from the group consisting of: silicon nanoparticles; silicon microparticles; SiOxnanoparticles, wherein 0 < x < 2; SiO x microparticles, wherein 0 < x < 2; and silicon-carbon composites, and the chemical formula of the nickel cobalt manganese in the cathode is LiNi x Co y Mn 1-x-y O2, wherein x > 0.
7.