All-solid-state battery using non-carbon-based tungsten oxide cathode additive having high conductivity and high safety

Abstract

Disclosed is an all-solid-state battery using a non-carbon-based tungsten oxide cathode additive having high conductivity and high safety. The cathode additive according to an embodiment comprises a tungsten oxide having an oxygen vacancy, and the tungsten oxide can replace a carbon-based conductive material in a cathode composite compound for an all-solid-state battery.

Description

All-solid-state battery using non-carbon high-conductivity and high-safety tungsten oxide cathode additive

[0001] The following description relates to a non-carbon-based high-conductivity and high-safety tungsten oxide cathode additive, and an all-solid-state battery using the cathode additive.

[0002] All-solid-state batteries have higher energy density and safety than lithium-ion batteries by using a lithium metal anode and a non-flammable solid electrolyte. Many companies are currently conducting research and development for use in next-generation energy storage systems for medium and large-scale applications such as electric vehicles and energy storage systems (ESS). Among the developed solid electrolytes, sulfide-based solid electrolytes in particular have excellent ionic conductivity (∼10) comparable to that of organic liquid electrolytes. -2 S cm -1) and has better formability than other inorganic solid electrolytes, so it has attracted much attention in all-solid-state batteries. However, the narrow electrochemical stability window of the sulfide-based solid electrolyte degrades the stability of the anode / solid electrolyte and cathode / solid electrolyte interfaces, as well as the interfacial stability of the components within the anode, resulting in rapid capacity decline. In practical all-solid-state battery cells, conductive additives are essential to improve electronic conduction. However, when high-nickel oxide cathode materials and carbon-based conductive additives are used simultaneously in sulfide-based solid electrolytes, the electrochemical instability at high voltages promotes the decomposition of the electrolyte. One of the many strategies to solve the interfacial problem of sulfide-based solid electrolytes is to coat the anode surface with lithium metal oxide to prevent direct exposure of the electrode material to the solid electrolyte. As a result, the occurrence of side reactions in the electrolyte is prevented, and the cycling stability of all-solid-state batteries is greatly improved, leading to widespread industrial use. Currently, there are two methods for coating lithium metal oxide on the anode surface: wet and dry processes. The wet process, which involves mixing the cathode active material and precursor in a solvent and calcining them, is widely used as a cathode surface coating method. However, the wet process has the problem of affecting the structure of the cathode active material because both the cathode active material and precursor are placed in a solvent and calcined at high temperatures to coat the surface. The dry process mixes the cathode active material and coating material using dedicated equipment and coats the cathode surface. However, the dry process has the problem of low economic feasibility due to the difficulty in coating in large quantities.

[0003] Provided are a non-carbonaceous, high-conductivity and high-safety tungsten oxide cathode additive and an all-solid-state battery using the cathode additive.

[0004] A non-carbonaceous cathode additive is provided, characterized in that it comprises tungsten oxide in which oxygen deficiency is formed, and the tungsten oxide replaces a carbonaceous conductive material of a cathode composite compound of an all-solid-state battery.

[0005] According to one aspect, the tungsten oxide may be characterized by including black tungsten oxide strengthened by oxygen deficiency.

[0006] According to another aspect, the tungsten oxide may be characterized in that an oxygen deficiency is formed by breaking the bond between tungsten and oxygen by reducing and heat-treating a precursor solution containing a mixture of a polymer and tungsten chloride.

[0007] According to another aspect, the polymer may be characterized in that it includes polyvinylpyrrolidone (PVP), and the tungsten chloride includes WCl6.

[0008] According to another aspect, the reduction heat treatment may be characterized by including a heat treatment process of first calcining at 300°C in an air atmosphere and second calcining at 650°C in a hydrogen and argon atmosphere.

[0009] According to another aspect, the tungsten oxide may be characterized by forming an OH hydroxyl group when water or water molecules are adsorbed by the formation of the oxygen deficiency.

[0010] According to another aspect, the tungsten oxide may be characterized in that the band gap is reduced by the formation of the oxygen deficiency, thereby increasing the electronic conductivity.

[0011] According to another aspect, the tungsten oxide may be mixed as a conductive material into the positive electrode composite compound and added to the positive electrode composite compound.

[0012] According to another aspect, the tungsten oxide may be characterized by reducing the interfacial resistance of the all-solid-state battery by replacing the carbon-based conductive material and alleviating the decomposition of the solid electrolyte promoted by the carbon-based conductive material.

[0013] A cathode composite compound for an all-solid-state battery is provided, characterized by a non-carbonaceous cathode additive replacing a carbonaceous conductive material of a cathode composite compound of an all-solid-state battery with tungsten oxide in which oxygen deficiency is formed; a cathode active material; and a solid electrolyte being mixed.

[0014] An all-solid-state battery is provided, characterized in that it includes a non-carbonaceous cathode additive that replaces a carbonaceous conductive material of an all-solid-state battery cathode composite compound with tungsten oxide in which oxygen deficiency is formed; a cathode active material; and a cathode composite compound mixed with a solid electrolyte as a cathode.

[0015] A non-carbon-based high-conductivity and high-safety tungsten oxide cathode additive and an all-solid-state battery using the cathode additive can be provided.

[0016] Figure 1 is a black WO reinforced with oxygen vacancy according to one embodiment of the present invention. 3-x This is a drawing showing an example of an all-solid-state battery in which a cathode protective additive is introduced.

[0017] Figure 2 is a black WO reinforced with oxygen deficiency according to one embodiment of the present invention. 3-x This is a drawing showing an example of the manufacturing process of an all-solid-state battery in which a cathode protective additive is introduced.

[0018] FIG. 3 is a drawing showing an example of a conventional all-solid-state battery using conductive carbon and an example of an all-solid-state battery according to an embodiment of the present invention that does not use conductive carbon.

[0019] Figure 4 is a diagram showing a yellow WO3 and a black WO having an oxygen-deficient structure according to an embodiment of the present invention. 3-xThis is a graph showing examples of XRD (X-ray diffraction) analysis results for each.

[0020] Figure 5 is a graph showing a yellow WO3 and a black WO having an oxygen-deficient structure according to an embodiment of the present invention. 3-x This graph shows examples of XPS (X-ray Photoelectron Spectroscopy) analysis results for each.

[0021] Figure 6 is a graph showing a yellow WO3 and a black WO having an oxygen-deficient structure according to an embodiment of the present invention. 3-x This graph shows examples of UV-vis (Ultraviolet-visible) analysis results for each.

[0022] Figure 7 is a graph showing a yellow WO3 and a black WO having an oxygen-deficient structure according to an embodiment of the present invention. 3-x This graph shows examples of ESR (Electron Spin Resonance) analysis results for each.

[0023] Figure 8 is a graph showing examples of XRD analysis results for various bipolar complex compounds.

[0024] Figures 9 to 11 are graphs showing examples of battery performance for various positive electrode composite compounds.

[0025] Figures 12 to 16 are drawings showing an embodiment of the present invention, in which CNF (Carbon Nanofiber) and Black WO 3-x These graphs illustrate examples of cycle performance according to the ratio of .

[0026] FIG. 17 and FIG. 18 are graphs illustrating the cycle performance of NMC / CNF and NMC / Black WO3-X according to an embodiment of the present invention.

[0027] Figures 19 and 20 are graphs showing examples of EIS (Electrochemical Impedance Spectroscopy) analysis results according to positive electrode additives.

[0028] Figures 21 and 22 show lithium ion (L + ) are graphs showing examples of the results of the Galvanostatic Intermittent Titration Technique (GITT) test to check the mobility of the .

[0029] Figure 23 is a graph showing an example of XPS analysis results before and after 50 cycles of charge and discharge.

[0030] The present invention can be modified in various ways and has various embodiments. Hereinafter, specific embodiments will be described in detail based on the attached drawings.

[0031] In describing the present invention, if it is determined that a detailed description of a related known technology may obscure the gist of the present invention, the detailed description is omitted.

[0032] In embodiments of the present invention, a highly conductive additive synthesized through heat treatment of a solution containing a polymer and a precursor can be utilized by adding it to the cathode composite compound instead of the carbon-based conductive additive, rather than coating the cathode surface. Therefore, compared to the existing wet and dry processes, this method of simply adding and mixing the highly conductive additive into the cathode composite compound not only physically prevents contact between the high-nickel oxide cathode and the solid electrolyte, but also maintains electrical conductivity through low band gap energy and facilitates charge transfer between active materials, thereby providing high structural stability. Therefore, embodiments of the present invention can not only solve the cathode / solid electrolyte interface problem, but also be economical because they can be manufactured in large quantities. In the current situation where the commercialization of all-solid-state batteries is imminent, the embodiments of the present invention, which have a simplified process and do not affect the structure of the cathode active material and electrolyte side reactions, can solve the interface problem between the cathode and the solid electrolyte of all-solid-state batteries in a cost-competitive manner.

[0033] For more specific examples, all-solid-state batteries present various interfacial problems. Among them, the interfacial problem of the positive electrode complex compound is a serious one. During battery charging and discharging, the active material expands and contracts due to the insertion and deintercalation of lithium ions, resulting in poor contact with the solid electrolyte. Repeatedly, this process exerts strong stress on the active material, causing cracks. Furthermore, the uneven contact between the active material and the solid electrolyte increases the electron-ion distance compared to lithium-ion batteries, resulting in reduced electronic and ionic conductivity. Sulfide-based solid electrolytes have a narrow electrochemical stability window. Therefore, when a high-nickel oxide positive electrode and a carbon-based conductive material are used simultaneously, the sulfide-based solid electrolyte undergoes electrolyte oxidation and decomposition (side reactions) at high voltages during charging, generating byproducts. This creates an unstable interface, increasing interfacial resistance. Therefore, using a carbon-based conductive material as it is can cause serious decomposition of the sulfide-based solid electrolyte during the charging process, which can lead to the formation of an undesirable interfacial layer within the cathode composite compound, which can negatively affect cell performance. Therefore, it is very important to use an appropriate conductive additive other than carbon. In the embodiments of the present invention, WO with high conductivity and durability is used as a cathode composite compound for an all-solid-state battery. 3-x The interfacial problem between the sulfide-based solid electrolyte and the anode can be solved by introducing particles as a cathode framework stabilizing additive.

[0034] In one embodiment, a non-carbonaceous cathode additive may be provided, characterized in that it includes tungsten oxide in which oxygen deficiency is formed, and the tungsten oxide replaces a carbonaceous conductive material of a cathode composite compound of an all-solid-state battery. At this time, the tungsten oxide may be characterized in that it includes black tungsten oxide strengthened by oxygen deficiency. In addition, the tungsten oxide may be characterized in that the oxygen deficiency is formed by reducing heat treatment of a precursor solution mixed with a polymer and tungsten chloride to break the bond between tungsten and oxygen. In addition, the polymer may be characterized in that it includes polyvinylpyrrolidone (PVP), and the tungsten chloride may include WCl6. In addition, the reducing heat treatment may be characterized in that it includes a heat treatment process of first calcining at 300°C in an air atmosphere and second calcining at 650°C in a hydrogen and argon atmosphere. In addition, the tungsten oxide may be characterized by forming an OH hydroxyl group when water or water molecules are adsorbed by the formation of the oxygen deficiency. In addition, the tungsten oxide may be characterized by being converted to have a band gap reduced by the formation of the oxygen deficiency and thus have increased electron conductivity. In addition, the tungsten oxide may be characterized by being mixed as a conductive material into the positive electrode composite compound and added to the positive electrode composite compound. In addition, the tungsten oxide may be characterized by replacing the carbon-based conductive material and alleviating the decomposition of the solid electrolyte promoted by the carbon-based conductive material, thereby reducing the interfacial resistance of the all-solid-state battery.

[0035] In another embodiment, a cathode composite compound for an all-solid-state battery may be provided, characterized by a non-carbonaceous cathode additive replacing a carbonaceous conductive material of the cathode composite compound of an all-solid-state battery with tungsten oxide in which oxygen deficiency is formed; a cathode active material; and a solid electrolyte mixed therein.

[0036] In another embodiment, an all-solid-state battery can be provided, characterized in that it includes a non-carbonaceous cathode additive that replaces a carbonaceous conductive material of an all-solid-state battery cathode composite compound with tungsten oxide in which oxygen deficiency is formed; a cathode active material; and a cathode composite compound mixed with a solid electrolyte as the cathode.

[0037] Figure 1 is a black WO reinforced with oxygen vacancy according to one embodiment of the present invention. 3-x This is a drawing showing an example of an all-solid-state battery that introduces a cathode protective additive. The all-solid-state battery (100) may include a cathode composite mixture (110), a solid electrolyte (120), and an anode (130). The cathode composite mixture (110) may include NMC (Nickel, Manganese, Cobalt, 111), and black tungsten oxide (hereinafter referred to as "black WO") strengthened by oxygen deficiency. 3-x ", 112). The solid electrolyte (120) may include, for example, Li6PS5Cl, but is not limited thereto.

[0038] Figure 2 is a black WO reinforced with oxygen vacancy in one embodiment of the present invention. 3-x This is a drawing showing an example of a manufacturing process of an all-solid-state battery that introduces polyvinylpyrrolidone (PVP) and tungsten (VI) chloride (WCl6) as a cathode protective additive. In Fig. 2, a precursor solution mixed with polyvinylpyrrolidone (PVP) and tungsten (VI) chloride (WCl6) is stirred, then calcined at 300°C in an air atmosphere for the first time, and then calcined at 650°C in a hydrogen and argon atmosphere for the second time to form black tungsten oxide (hereinafter referred to as "black WO) strengthened by oxygen deficiency. 3-x ") is shown as an example of manufacturing black WO 3-xUnlike conventional tungsten oxide (hereinafter referred to as Yellow WO3), it intentionally breaks the bond between tungsten and oxygen through reduction heat treatment to form an oxygen deficiency, and due to this oxygen deficiency formation, the band gap is reduced, so it can be converted into a material with excellent electronic conductivity. Afterwards, the manufactured black WO 3-x can be added to the cathode composite compound as a cathode protective additive. Such black WO 3-x Due to its high conductivity, it can replace the carbon that was previously used in the anode. Non-carbon tungsten oxide with this oxygen deficiency formation can form OH hydroxyl groups when water or water molecules are adsorbed due to the oxygen deficiency formation.

[0039] Figure 3 is a diagram illustrating an example of a conventional all-solid-state battery using conductive carbon and an example of an all-solid-state battery according to an embodiment of the present invention that does not use conductive carbon. Conventional all-solid-state batteries have problems such as increased electrolyte degradation after charge / discharge cycling, decreased cycle safety, increased interface impedance, and decreased coulombic efficiency. On the other hand, black WO using conductive carbon 3-x An all-solid-state battery according to an embodiment of the present invention, in which a positive electrode composite compound is added by replacing the electrolyte, exhibits a stable interface with reduced electrolyte degradation, increased cycle safety, reduced interface impedance, and increased Coulombic efficiency. In addition, ionic conductivity is also improved. The specific details of these results will be described in more detail below.

[0040] In this way, in embodiments of the present invention, a non-carbonaceous, highly conductive tungsten oxide additive can be synthesized and applied as an additive to an all-solid-state battery instead of a carbon conductive material.

[0041] Figure 4 is a diagram showing a yellow WO3 and a black WO having an oxygen-deficient structure according to an embodiment of the present invention. 3-xThis is a graph showing an example of the XRD (X-ray diffraction) analysis results for each, and FIG. 5 shows the results of Yellow WO3 and black WO having an oxygen-deficient structure according to an embodiment of the present invention. 3-x This is a graph showing an example of the XPS (X-ray Photoelectron Spectroscopy) analysis results for each. According to the XRD analysis results in Fig. 4, Yellow WO3 has a crystalline structure because the bonds between tungsten and oxygen are all connected, whereas Black WO 3-x It can be confirmed that some of the bonds between tungsten and oxygen are broken through the reduction heat treatment, resulting in an amorphous structure (or weakly crystalline structure) and the formation of oxygen deficiencies. According to the XPS analysis results in Fig. 5, in the W 4f peak, Yellow WO3 shows some reduction peaks, while Black WO 3-x is W 4+ , W 5+ We can see that the reduction pick has increased significantly, confirming that the oxygen deficiency has been formed well. The O 1s pick is also W 4+ , W 5+ It can be seen that the oxygen peaks combined with tungsten in black WO have increased. 3-x You can see that it is well synthesized.

[0042] Figure 6 is a graph showing a yellow WO3 and a black WO having an oxygen-deficient structure according to an embodiment of the present invention. 3-x A graph showing an example of UV-vis (Ultraviolet-visible) analysis results for each, and Fig. 7 shows Yellow WO3 and black WO having an oxygen-deficient structure according to an embodiment of the present invention. 3-x This is a graph showing examples of ESR (Electron Spin Resonance) analysis results for each. In the UV-vis analysis results in Fig. 6, Yellow WO3 and black WO 3-xIt shows the difference in pick due to the color difference between the liver. In other words, black WO 3-x The absorption rate of Yellow WO3 is higher than that of Black WO3, so Yellow WO3 and Black WO 3-x This may mean that there is a distinct color difference. In addition, the ESR analysis results in Fig. 7 show that black WO is higher than yellow WO3. 3-x In this case, a sharper pick (relatively clearer g1 signal) appears, which is better for black WO than for Yellow WO3. 3-x This may mean that oxygen deficiency is relatively more created in black WO 3-x This may mean that the synthesis was successful.

[0043] Fig. 8 is a graph showing examples of XRD analysis results for various positive electrode composite compounds, and Figs. 9 to 11 are graphs showing examples of battery performance for various positive electrode composite compounds. Conductive materials such as a conductive agent, a positive electrode active material, and a solid electrolyte can be mixed into the positive electrode of an all-solid-state battery.

[0044] At this time, Fig. 8 shows a Kapton tape-based anode composite compound, a NMC (Nickel-Manganese-Cobalt)-based anode composite compound, a NMC / Yellow WO3-based anode composite compound, and a NMC / black WO 3-x The XRD analysis results for each of the bipolar composite compounds based on the present invention are shown. The XRD analysis results in Fig. 8 are black WO having an oxygen-deficient structure according to an embodiment of the present invention. 3-x It can be proven that it does not cause structural changes because it is present in very small amounts.

[0045] In addition, in FIGS. 9 to 11, a cathode composite compound including NMC, a cathode composite compound including NMC / Yellow WO3, and NMC / Black WO 3-xThe battery cycle performance for each cathode composite compound including NMC / Yellow WO3 (74.0%) > NMC / Black WO is shown. The initial coulombic efficiency is 74.0% for NMC / Yellow WO3 > 74.0% for NMC / Black WO. 3-x (73.1%) > NMC (69.6%) in the order (Fig. 10), and the first cycle discharge capacity (mAh / g) was NMC / Black WO 3-x (156mAh / g) > NMC (154mAh / g) > NMC / Yellow WO3 (149mAh / g) (Fig. 9 and Fig. 11), and the capacity retention after 50 cycles is NMC / Black WO 3-x (84.1%) > NMC / Yellow WO3 (81.3%) > NMC (79.7%) (Fig. 9), and the rate capability is NMC / Black WO 3-x > NMC > NMC / Yellow WO3 (Fig. 11) respectively. As such, the graphs of Figs. 9 to 11 show black WO having an oxygen-deficient structure according to an embodiment of the present invention. 3-x It has been shown that an all-solid-state battery containing a bipolar composite compound has the best battery performance.

[0046] Figures 12 to 16 are drawings showing an embodiment of the present invention, in which CNF (Carbon Nanofiber) and Black WO 3-x These are graphs showing examples of cycle performance according to the ratio of . For example, 5WO 3-X / 3CNF is Black WO in the entire anode composite mixture (100%) 3-x It can mean that the ratio of CNF and 0WO3-x is 5wt%:3wt%. 0WO3-x is Black WO 3-x This may be the same as using NMC without this inclusion.

[0047] According to Fig. 12, the capacity retention after 50 cycles is 5WO 3-X / 3CNF(84.0%) > 15WO 3-X / 0CNF(83.2%) > 12WO 3-X / 0CNF(82.6%) > 0WO 3-X / 3CNF(79.7%) > 1WO 3-X / 3CNF(78.7%) order. Also, according to Fig. 12, the first cycle discharge capacity (mAh / g) is 15WO 3-X / 0CNF(161.1mAh / g) > 5WO 3-X / 3CNF(155.3mAh / g) > 0WO 3-X / 3CNF(154.5mAh / g) > 1WO 3-X / 3CNF(153.7mAh / g) > 12WO 3-X / 0CNF(148.4mAh / g) order. Battery performance is Black WO 3-x If only included (15WO) 3-X / 0CNF) can be seen to be the highest.

[0048] Also, according to Fig. 13, the first cycle irreversible capacity is 1WO 3-X / 3CNF(75.7mAh / g) > 5WO 3-X / 3CNF(69.7mAh / g) > 0WO 3-X / 3CNF(67.4mAh / g) > 15WO 3-X / 0CNF(57.9mAh / g) > 12WO 3-X / 0CNF(57.0mAh / g) order. At this time, Black WO 3-x If only included (15WO) 3-X / 0CNF) is when only existing NMC is used (0WO) 3-X It can be seen that the irreversible capacity is greatly reduced compared to / 3CNF.

[0049] Also, according to Fig. 14, the initial Coulomb efficiency is 15WO 3-X / 0CNF(73.6%) > 12WO 3-X / 0CNF(72.2%) > 0WO 3-X / 3CNF(69.6%) > 5WO 3-X / 3CNF(69.0%) > 1WO 3-X / 3CNF(67.0%) is shown in the order. At this time, Black WO 3-x If only included (15WO) 3-X / 0CNF) is when only existing NMC is used (0WO) 3-X It can be seen that the initial Coulombic efficiency also increases compared to / 3CNF.

[0050] Also, according to Figs. 15 and 16, when DC polarization was calculated by applying a current of 200 mV, the electronic conductivity of the bipolar composite compound was 5WO. 3-X / 3CNF > 1WO 3-X / 3CNF > 0WO 3-X / 3CNF > 15WO 3-X / 0CNF > 12WO 3-X / 3CNF order is shown.

[0051] According to Ohm's law, V=I SS R, ρ=RA / L, σ=1 / ρ, where V is the applied voltage, I SS can represent steady-state current, A represents electrode area, and L represents electrode thickness, respectively. Here, conductive materials (CNF, and Black WO 3-X ) It can be seen that the electrical conductivity increases as the content increases.

[0052] Figures 17 and 18 are NMC / CNF and NMC / Black WO according to one embodiment of the present invention. 3-X These are graphs illustrating the cycle performance of NMC / Black WO. According to Figs. 17 and 18, the first cycle discharge capacity (mAh / g) is NMC / Black WO 3-X (161 mAh / g) > NMC / CNF (154 mAh / g), and the capacity retention after 50 cycles is NMC / Black WO 3-X (83.2%) > NMC / CNF (79.7%), indicating the order of Black WO 3-X It can be seen that when added, it shows relatively better cycle performance.

[0053] Figures 19 and 20 are graphs showing examples of EIS (Electrochemical Impedance Spectroscopy) analysis results according to the positive electrode additive. The analysis results show that the resistance after 50 charge / discharge cycles is R CA-CA A NMC / CNF (6.4 Ω) > NMC / Black WO 3-X (5.4 Ω) in the order of R CA-SE A NMC / CNF (82.5 Ω) > NMC / Black WO 3-X (63.9 Ω). Here, R CA-CA is the ionic resistance of the bipolar complex compound, R CA-SE can represent the anode / SE interface resistance, CA can represent the cathode, and SE can represent the solid electrolyte. This is because the carbon promotes the decomposition of LPSCl (lithium phosphorus sulfur chloride) and forms an interfacial layer between the SE-AM in the cathode complex, thereby increasing the interfacial resistance. This means that the problem of increased interfacial resistance can be significantly reduced by using a non-carbonaceous, highly conductive tungsten oxide cathode additive. AM can represent the active material.

[0054] Figures 21 and 22 show lithium ion (L + ) are graphs showing examples of the results of the Galvanostatic Intermittent Titration Technique (GITT) test to confirm the mobility of NMC / CNF and NMC / Black WO. In Figs. 21 and 22, both the overvoltage and lithium ion mobility are shown for NMC / CNF and NMC / Black WO. 3-X You can see that it operates almost similarly, and in the case of charging, lithium-ion mobility is NMC / Black WO 3-X You can see that it is better.

[0055] For example, lithium ion mobility can be calculated as in Equation 1.

[0056]

[0057] Here, τ is the pulse duration, m is the mass of the active material of the working electrode, and V m is the molar volume, M is the molar mass of the active material of the working electrode, S is the cell interfacial area, ΔE s is the change in normal voltage after relaxation for 1 hour, ΔE τ can mean the transient voltage change after a 10-minute charge / discharge process, respectively.

[0058] Figure 23 is a graph showing examples of XPS analysis results before and after 50 cycles of charge and discharge. Figure 23 shows how the electrolyte decomposition reaction occurred through XPS analysis results inside the positive electrode composite compound. In each graph, the upper two data are XPS analysis results for the sample with added CNF before and after 50 cycles, and the lower two data are XPS analysis results for the sample with Black WO 3-X The XPS analysis results for the samples with added ions before and after 50 cycles are shown respectively.

[0059] PS4 on S 2p 3- The peaks are related to the LPSCI electrolyte, Li2S, S, SO4 2- The peak may indicate SE oxidation and decomposition during cycling. Also, PS4 at P 2p 3- The peaks are associated with LPSCI electrolytes, P2S5, PO4 3- The peaks may indicate the interfacial reactivity of SE-AM due to SE oxidation and decomposition during cycling. Also, Li2S, S, SO4 2- P2S5, PO4 3- Peak intensity is NMC / CNF > NMC / Black WO 3-X, which may imply that carbon promotes the decomposition of LPSCI. The side reaction products form an interfacial layer between SE-AM in the anode complex compound, thereby increasing the interfacial resistance and reducing the electrochemical performance.

[0060] Additionally, as shown in Table 1 below, after cycling, W 4+ / W 5+ / W X+ The peak intensity decreased from 35% to 27.5%.

[0061] Integrated area (%)W 6+ W 4+ / W 5+ / W X+ Before cycling65.035.0After cycling72.527.5

[0062] This is W due to lattice oxygen 4+ / W 5+ / W X+ Black WO due to oxidation of 3-X It can alleviate the decomposition of SE at high voltage, prevent the oxidation of SE by active oxygen released from the anode during cycling, and consequently improve the stability of the anode interface.

[0063] According to embodiments of the present invention, a non-carbonaceous high-conductivity and high-safety tungsten oxide cathode additive and an all-solid-state battery using the cathode additive can be provided.

[0064] The above description is merely an illustrative illustration of the technical idea of ​​the present invention, and those skilled in the art will appreciate that various modifications and variations can be made without departing from the essential characteristics of the present invention. Therefore, the embodiments described in the present invention are intended to illustrate, rather than limit, the technical idea of ​​the present invention, and the present invention is not limited to these embodiments. The scope of protection of the present invention should be interpreted by the following claims, and all technical ideas within a scope equivalent thereto should be interpreted as being included within the scope of the rights of the present invention.

Claims

1. Contains tungsten oxide formed by oxygen deficiency, Replacing the carbon-based conductive material of the positive electrode composite compound of an all-solid-state battery with the above tungsten oxide A non-carbon anode additive characterized by:

2. In paragraph 1, A non-carbon anode additive characterized in that the above tungsten oxide comprises black tungsten oxide strengthened by oxygen deficiency.

3. In paragraph 1, The above tungsten oxide is a non-carbon anode additive characterized in that an oxygen deficiency is formed by breaking the bond between tungsten and oxygen through reduction heat treatment of a precursor solution mixed with a polymer and tungsten chloride.

4. In paragraph 3, The above polymer contains polyvinylpyrrolidone (PVP), The above tungsten chloride comprises WCl6. A non-carbon anode additive characterized by:

5. In paragraph 3, A non-carbon-based cathode additive characterized in that the above reduction heat treatment includes a heat treatment process of primary calcination at 300°C in an air atmosphere and secondary calcination at 650°C in a hydrogen and argon atmosphere.

6. In paragraph 1, The above tungsten oxide is a non-carbon anode additive characterized in that it forms an OH hydroxyl group when water or water molecules are adsorbed by the formation of the oxygen deficiency.

7. In paragraph 1, A non-carbon-based cathode additive characterized in that the tungsten oxide is converted to have a reduced band gap and increased electronic conductivity by the formation of the oxygen deficiency.

8. In paragraph 1, A non-carbon-based cathode additive characterized in that the tungsten oxide is mixed as a conductive material into the cathode composite compound and added to the cathode composite compound.

9. In paragraph 1, A non-carbon-based cathode additive characterized in that the tungsten oxide replaces the carbon-based conductive material and reduces the interfacial resistance of the all-solid-state battery by alleviating the decomposition of the solid electrolyte promoted by the carbon-based conductive material.

10. A non-carbonaceous cathode additive that replaces the carbonaceous conductive material of the cathode composite compound of an all-solid-state battery with tungsten oxide in which oxygen deficiency is formed; positive electrode active material; and solid electrolyte A cathode composite compound for an all-solid-state battery characterized by this mixing.

11. In paragraph 10, A cathode composite compound for an all-solid-state battery, characterized in that the tungsten oxide comprises black tungsten oxide strengthened by oxygen deficiency.

12. In paragraph 10, The above tungsten oxide is a cathode composite compound for an all-solid-state battery, characterized in that an oxygen deficiency is formed by breaking the bond between tungsten and oxygen by reducing and heat-treating a precursor solution containing a mixture of a polymer and tungsten chloride.

13. In paragraph 10, The above tungsten oxide is a cathode composite compound for an all-solid-state battery, characterized in that it forms an OH hydroxyl group when water or water molecules are adsorbed by the formation of the oxygen deficiency.

14. In paragraph 10, A cathode composite compound for an all-solid-state battery, characterized in that the tungsten oxide is converted to have a reduced band gap and increased electronic conductivity by the formation of the oxygen deficiency.

15. A non-carbonaceous cathode additive that replaces the carbonaceous conductive material of the cathode composite compound of an all-solid-state battery with tungsten oxide in which oxygen deficiency is formed; positive electrode active material; and solid electrolyte Including this mixed positive electrode complex compound as the positive electrode An all-solid-state battery characterized by .

16. In paragraph 15, An all-solid-state battery characterized in that the tungsten oxide comprises black tungsten oxide enhanced by oxygen deficiency.

17. In paragraph 15, The above tungsten oxide is an all-solid-state battery characterized in that an oxygen deficiency is formed by breaking the bond between tungsten and oxygen by reducing and heat-treating a precursor solution mixed with a polymer and tungsten chloride.

18. In paragraph 15, An all-solid-state battery characterized in that the tungsten oxide forms an OH hydroxyl group when water or water molecules are adsorbed by the formation of the oxygen deficiency.

19. In paragraph 15, An all-solid-state battery characterized in that the tungsten oxide is converted to have a reduced band gap and increased electronic conductivity by the formation of the oxygen deficiency.

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