Electrochemical waste solution lithium recovery system preventing solid electrolyte reduction using a cation exchange membrane

This technology is an electrochemical cell structure for recovering lithium from waste solutions, featuring a cation exchange membrane placed between a metalloid or transition metal-based solid electrolyte membrane and the anode. This prevents the reduction and discoloration of metal ions on the surface of the solid electrolyte.

Conventional electrochemical cells for lithium recovery have faced issues where electrons moving to the anode during operation are injected into the solid electrolyte membrane. This causes Ge4+ and Ti4+ ions to reduce to Ge2+ and Ti3+, leading to discoloration of the electrolyte membrane and degradation of performance.

This technology physically blocks electron movement by placing an electrically insulating cation exchange membrane between the anode and the solid electrolyte membrane. It also utilizes a solid electrolyte membrane manufactured at a quenching temperature of 350–400°C, which is free of (Ge, Si)O2 secondary phases, thereby improving both ionic conductivity and mechanical strength. Applicable to waste battery recycling plants and LAS circular resource processing, it allows for the direct recovery of lithium as LiOH and Li2CO3 while extending the replacement cycle of the electrolyte membrane.

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Key Features:

• A solid electrolyte membrane positioned between the anode and cathode, containing a main crystalline phase and an AlPO4 secondary phase without the (Ge, Si)O2 secondary phase
• A separator positioned between the cathode and the solid electrolyte membrane, composed of a polyethylene film laminate or non-woven fabric impregnated with an organic electrolyte
• A cation exchange membrane placed in contact between the anode and the solid electrolyte membrane to prevent the reduction of Ge4+ and Ti4+ ions
• A step of filling the reservoir with waste solution to precipitate lithium metal at the cathode, followed by adding water and discharging to obtain lithium salts

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This invention was developed with support from the Ministry of Trade, Industry and Energy for the development of core technologies and key materials for an eco-friendly electrochemical recovery system to produce high-purity lithium and lithium compounds for lithium-ion batteries from LAS circular resources.

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Long-life high-nickel cathode material with superlattice ordering induced by grain boundary fluorine coating

This technology controls the nickel oxidation state (Ni2+/Ni3+) by coating the grain boundaries of high-nickel cathode active materials with fluorine and applying heat treatment. It enhances structural stability by creating a long-range ordered superlattice structure through ion site swapping between the lithium and transition metal layers.

While high-nickel cathode active materials offer high capacity, they suffer from side reactions with the electrolyte during repeated charge-discharge cycles. Furthermore, they face limitations in lifespan due to structural collapse caused by H2-H3 phase transitions and microcracks within particles that obstruct lithium-ion pathways.

This technology forms a fluorine-containing coating layer on particle surfaces and grain boundaries using materials like ammonium fluoride, followed by heat treatment to adjust the Ni2+ ratio to 49–130%. This induces regular site swapping between lithium and nickel, creating an ordered structure with alternating mixed layers that prevents layered structure collapse during long-term cycling. Applicable to high-nickel cells for long-range EVs and high-power power tool batteries, it allows for higher nickel content while slowing capacity degradation caused by microcracks.

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Key Features:

• Layered cathode active material comprising a lithium layer consisting only of lithium and a transition metal layer consisting only of transition metals including nickel
• Transition metal layer where the nickel oxidation state is adjusted such that the Ni2+ to Ni3+ ratio increases as the fluorine content increases
• Grain coating layer comprising fluorine at the grain boundary of at least one primary particle in a secondary particle composed of multiple primary particles
• Superlattice formed by alternating layers of a first mixed layer with higher lithium content and a second mixed layer with higher transition metal content

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High-transference number solid electrolyte based on quaternary ammonium-fixed network polymers and cationic nanoparticles

This technology is a solid electrolyte that enhances both lithium-ion transference number and ionic conductivity by dispersing cationic inorganic nanoparticles, surface-treated with a metal oxide layer, into a network polymer matrix formed by photocuring monomers containing quaternary ammonium groups and multifunctional monomers.

Conventional dual-ion conducting polymer electrolytes suffer from low lithium-ion transference numbers because both lithium cations and anions are mobile, leading to concentration gradients and cell polarization that degrade battery performance. Furthermore, existing solid electrolytes have high interfacial resistance with electrodes and are unstable with lithium metal anodes, resulting in dendrite growth.

This technology fixes quaternary ammonium cation functional groups to the polymer backbone to suppress anion movement and maximize selective lithium-ion transport, while incorporating TiO2 and SiO2-coated cationic inorganic nanoparticles to reinforce interfacial stability and ionic conductivity. Additionally, it minimizes interfacial resistance by integrating the electrolyte and electrode through a solvent-free printing process. It can be applied to lithium metal batteries operating above 4V and the manufacturing of thin-film/flexible batteries based on printing processes, reducing cell polarization and enabling the production of integrated electrode-electrolyte cells without solvent drying equipment.

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Key Features:

• Network polymer polymerized from a photocurable composition containing monomers with quaternary ammonium groups and multifunctional monomers
• Cationic inorganic nanoparticles coated with a metal oxide layer containing titanium dioxide and silicon dioxide, dispersed within the network polymer
• Electrolyte included at 50–300 parts by weight, along with 10–300 parts by weight of inorganic nanoparticles per 100 parts by weight of the photocurable composition
• Step of forming a solid electrolyte by printing the curable composition with dispersed inorganic nanoparticles onto a lithium metal layer and then photocuring it

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This invention was developed with support from the Ministry of Science and ICT for a single-ion conductor-based multidimensional free-form power system.

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Metal battery anode with suppressed dendrite growth using an aromatic lithium carboxylate host

This technology places a metal-storage host composed of metal-containing aromatic compounds, such as aromatic polycarboxylic acid metal salts, on a current collector. This provides uniform nucleation sites for metal ions and induces reversible plating and stripping to suppress dendrite growth.

Metal electrodes have historically suffered from dendrite growth due to uneven current distribution during charge and discharge cycles. These dendrites lead to electrolyte depletion, internal short circuits, volume expansion, and fire hazards, all of which limit battery lifespan.

This technology introduces an active material layer containing an aromatic polycarboxylic acid metal salt, such as lithium terephthalate, onto an anode current collector. It then forms an electrochemically plated metal thin film, just a few nanometers thick, to control the morphology of the plated metal and mitigate volume expansion. Applicable to lithium-metal batteries, anode-free cells, and high-energy-density power sources for drones and wearables, it reduces excess lithium usage while lowering short-circuit risks over long-term cycling.

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Key Features:

• An active material layer located on a current collector, comprising a metal-storage host made of a metal-containing aromatic compound
• A 3–18 nm thick lithium-containing metal thin film located on the active material layer and deposited via electrochemical methods
• Aromatic polycarboxylic acid lithium salt derived from one or more of phthalic acid, isophthalic acid, terephthalic acid, or naphthalenedicarboxylic acid
• A cathode spaced apart from the metal battery anode, and an electrolyte in contact with both the cathode and anode

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This invention was developed with support from the Ministry of Science and ICT for a single-ion conductor-based multidimensional free-form power system.

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Secondary Battery Life Prediction Analysis Technology Using Continual Learning to Mitigate Catastrophic Forgetting

This technology applies continual learning techniques when secondary battery data from different operating environments and types are input sequentially. It updates the analysis model for new data while retaining information from past data, eliminating the need to retrain existing models from scratch.

Existing deep learning-based battery life prediction models suffer from a sharp decline in performance when operating environments or battery types change after initial training. Retraining the entire dataset to address this increases computational costs and leads to catastrophic forgetting, where previous knowledge is lost.

This technology incorporates continual learning methods such as Elastic Weight Consolidation (EWC), Generative Replay, and Dynamic Expandable Networks. When input battery data—including operating environment, type, or initial defects—differs from existing data or exceeds a data volume threshold, the model undergoes continual learning to preserve past information while ensuring prediction accuracy for new conditions. It can be applied to EV battery diagnostic platforms and used-battery residual value assessment services, reducing the high costs of repeated large-scale retraining whenever new cell models are introduced.

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Key Features:

• A step where an analysis device acquires secondary battery information including at least one of the following: charge/discharge time, voltage, current, capacity, or temperature
• A step where the analysis model undergoes continual learning if the operating environment, type, or initial defect status of the acquired information differs from existing training data
• A step where the acquired secondary battery information is input into the continually learned analysis model to analyze life information based on the output
• A continual learning step applying at least one of EWC, Generative Replay, Dynamic Expandable Network, or Synaptic Intelligence

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This invention was developed with support from the Ministry of Trade, Industry and Energy for the development of low-cost, high-output VRFB stacks with a high current density of 200mA/cm2 or more.

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Reduced Graphene Stacking Anode for Sodium Storage with Expanded Interlayer Spacing Using AlOOH Sacrificial Spacers

This technology involves inserting metal oxyhydroxide particles, such as AlOOH, between reduced graphene oxide (rGO) sheets to adjust the interlayer spacing before removing the particles. This creates a layered graphene stack that facilitates the insertion and extraction of sodium ions.

Because sodium ions are larger than lithium ions, they struggle to enter the narrow interlayer spacing of conventional graphite electrodes. Graphene electrodes also face limitations, as the sheets tend to aggregate, making it difficult to secure the interlayer space required for ion diffusion and electric double-layer formation.

This technology involves adding a trivalent metal salt, such as aluminum halide, to a graphene oxide dispersion, followed by sequential reduction and heat treatment to grow nano-sized metal oxyhydroxide particles between the graphene layers. The particles are then removed using an acidic solvent to obtain a stack with wide interlayer spacing, corresponding to an XRD 2θ peak of 10° or less. Applicable to sodium-ion battery anodes and sodium hybrid capacitor electrodes, it provides a reversible storage space for large ions using only carbon materials, which was difficult to achieve with graphite.

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Key Features:

• Adding a reducing agent to a dispersion containing a trivalent metal salt and graphene oxide sheets to form reduced graphene oxide sheets
• Heat-treating the dispersion to form metal oxyhydroxide particles with an average diameter of 0.5 Å to 16.0 Å between the reduced graphene oxide sheets
• Removing the metal oxyhydroxide particles located between the sheets after heat treatment to secure interlayer space
• A reduced graphene oxide stack where the interlayer spacing in the direction normal to the sheets appears as a peak at 2θ 10° or less in XRD analysis

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This invention was developed with support from the Ministry of Trade, Industry and Energy for the development of extended layered sodium-ion secondary battery anode materials with long-range regularity using large polyatomic ion functionalized graphene ink.

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Tandem liquid metal battery maintaining an inert atmosphere via gasket channels and chamber gas lines

This technology features a structure where a gasket with integrated channels is placed at the housing interface of a liquid metal battery unit, connecting the interior of the battery unit to the chamber space. A single gas line outside the chamber removes internal air and injects inert gas to prevent explosion risks, while reducing gas bottlenecks and connection resistance during series connection.

Liquid metal batteries, where both electrodes and electrolytes are in a liquid state, pose an explosion risk if external air enters. Furthermore, when cells are connected in series for high-capacity applications, bottlenecks occur during gas injection and discharge, and electrical connection resistance between multiple cells increases.

This technology is configured to control gas exchange by providing channels in the gasket that connect the first and second internal spaces and connecting a gas line to the chamber. By setting different gasket channel directions for each series-connected battery unit and electrically connecting each housing to different points in the chamber, current flow overlap is reduced. It can be applied to large-capacity grid-connected ESS and long-duration storage facilities for renewable energy plants, ensuring that gas purging and wiring structures do not become complex even as the number of cells increases.

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Key Features:

• A unit cell provided in a first internal space formed by the coupling of a first housing and a second housing, operating in a liquid metal state
• A gasket provided at the housing coupling interface, having a channel that connects the first internal space to the space outside the housing
• A gas line that introduces or discharges gas into or from a second internal space between the chamber interior and the exterior of the coupled housing
• Gasket channels that provide flow paths in different directions for a plurality of series-connected liquid metal battery units

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This invention was developed with support from the Ministry of Trade, Industry and Energy for the cost reduction and component development of liquid metal secondary batteries for ESS.

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All-solid-state lithium metal anode with a crystalline Li2Se protective layer to prevent side reactions with sulfide electrolytes

This technology forms a crystalline lithium chalcogenide (e.g., Li2Se) nanostructure protective layer on the surface of a lithium metal anode. This layer prevents side reactions with sulfide-based solid electrolytes, thereby suppressing lithium dendrite growth and enhancing interface stability.

Lithium metal anodes and sulfide-based solid electrolytes are highly reactive, leading to side reactions during charging and discharging. This has historically caused dendrite growth and porous lithium deposition, resulting in battery short circuits and reduced cycle life.

This technology reacts chalcogen vapor on the lithium metal surface to form a crystalline Li2Se thin film in the form of nanorods or nanowalls. This protective layer ensures chemical bonding and stability with sulfide-based solid electrolytes. It can be applied to all-solid-state lithium metal batteries for electric vehicles and high-capacity next-generation cells, providing a solution that significantly reduces the risk of interface short circuits while utilizing lithium metal anodes.

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Key Features:

• An anode comprising a lithium metal layer and a protective layer, which is a lithium chalcogenide layer disposed on the lithium metal layer
• A cathode of a lithium secondary battery positioned opposite the anode with a sulfide-based solid electrolyte disposed therebetween
• A sulfide-based solid electrolyte disposed between the protective layer and the cathode to transport lithium ions
• A lithium chalcogenide layer where the lithium chalcogenide is Li2Se and is in the form of a crystalline thin film having (220) and (311) planes

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Large-Area Continuous Deposition of Sulfide Solid Electrolyte Thick Films via Cone-Jet Electrospray Process

This technology involves electrospraying a slurry of sulfide-based solid electrolyte powder dispersed in a non-reactive solvent, such as dichloroethane or dichlorobenzene, in cone-jet mode under a nitrogen atmosphere. This process forms uniform solid electrolyte or composite electrode thick films with excellent bonding properties on current collectors.

Conventional thin-film processes are costly due to high vacuum requirements, while pressing methods struggle with large-area scalability and interface quality. Casting methods also face limitations in controlling thickness and forming large-area films.

This technology achieves a stable cone-jet mode by maintaining an applied voltage-to-spray distance ratio of 1.0–1.5 kV/cm and a spray flow rate of 115–320 cm/h in a nitrogen atmosphere. By heating the current collector during deposition, it enhances the bonding and strength of the thick film without requiring a separate drying step. It enables the continuous stacking of composite slurries—including solid electrolytes, electrode materials, and conductive agents—to manufacture complete cells. Applicable to mass production lines and pilot coating equipment for all-solid-state batteries, it allows for the completion of cathode-electrolyte-anode stacks in a single process flow without vacuum equipment or high-pressure presses.

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Key Features:

• Preparation of a slurry by mixing sulfide-based solid electrolyte powder with at least one solvent from dichloroethane and dichlorobenzene in a weight ratio of 1:10 to 1:100
• Deposition of a lithium secondary battery thick film by electrospraying the slurry onto a current collector in cone-jet mode under a nitrogen atmosphere
• Heating the current collector while electrospraying the slurry during the deposition of the lithium secondary battery thick film
• Deposition of a lithium secondary battery solid electrolyte thick film by electrospraying a solid electrolyte slurry onto the first composite electrode thick film

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Lithium metal electrode with dendrite suppression via 2D Si-SiOx nanosheet protective layer

This technology involves coating the surface of a lithium metal electrode with a 2D silicon-silicon oxide (Si-SiOx) composite or transition metal oxide protective layer. This suppresses lithium dendrite growth and prevents side reactions between the lithium and the electrolyte.

Due to its high reactivity, lithium metal often causes side reactions with liquid electrolytes, leading to dendrite growth, initial overpotential increases, and risks of fire or explosion. Furthermore, existing protective layer processes like ALD or UV are costly and suffer from low productivity.

This technology utilizes a 1–20 nm thick, large-area 2D Si-SiOx composite—consisting of crystalline silicon bonded to sheet-like silicon oxide—or a transition metal oxide, mixed with a binder to create a slurry that is coated onto the lithium metal surface and dried. Applicable to lithium metal battery anodes, high-energy-density drones, and electric vehicle batteries, it offers the advantage of mass-producing protective layers via roll coating without expensive vacuum deposition equipment.

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Key Features:

• Large-area 2D silicon-silicon oxide composite with crystalline silicon bonded to sheet-like silicon oxide
• Lithium electrode for lithium secondary batteries coated with at least one selected from nickel oxide, copper oxide, and black titanium oxide
• Step of mixing the composite or transition metal oxide with a binder and solvent to create a slurry, then coating it onto the lithium metal surface
• Step of drying the slurry-coated lithium metal at a temperature of 60 to 150 °C for 2 to 10 hours

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This invention was developed with support from the Ministry of Science, ICT and Future Planning for non-flammable alkali metal secondary batteries based on organic-inorganic hybrid ionic liquid electrolytes.

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High-Voltage Stable Halide Solid Electrolyte Material with In-Situ Grown ZrO2 Nanonetwork

This technology is a halide-based nanocomposite that maximizes ionic conductivity and electrochemical stability by reacting lithium oxide precursors with metal halide precursors via mechanical milling, causing 5–10 nm ZrO2 to grow in-situ within the electrolyte and at the interface in a network structure.

Conventional sulfide-based solid electrolytes offer excellent ionic conductivity but suffer from low atmospheric stability and severe side reactions with cathode active materials in high-voltage environments. Existing halide-based electrolytes also face limitations in commercialization due to low ionic conductivity and high interfacial resistance.

This technology involves reacting lithium oxides (e.g., Li2O, LiNO3) with metal halides (e.g., ZrCl4) under specific mixing ratios and ball-milling conditions to produce a nanocomposite where 5–10 nm crystalline ZrO2 is formed in-situ within a Li-Zr-Cl host. It enhances ionic conductivity through the space-charge layer effect and improves interfacial stability and high-voltage cycle performance by blocking direct contact between sulfide electrolytes and the cathode. Applicable to cathode coating layers for all-solid-state batteries using high-nickel cathodes, sulfide-halide bilayer electrolytes, and cells for EVs and ESS, it prevents the decomposition of sulfide electrolytes during high-voltage operation, increasing cell design flexibility.

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Key Features:

• Halide-based nanocomposite for lithium-ion battery solid electrolytes represented by at least one of M1Oc-LiaM1Xb, LiX-LiaM1Xb, or M1Oc-LiX-LiaM1Xb
• Metal halide host where M1 is at least one of Ti, Zr, or Hf, and X is Cl, Br, F, or I
• ZrO2 nanocrystals with an average crystal size of 5–10 nm via TEM analysis, grown in-situ and formed as a network within the LiaM1Xb host
• Step of preparing a halide-based nanocomposite by solid-state mixing of a metal halide precursor with a lithium oxide precursor in an inert gas atmosphere

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Electric Vehicle Battery Thermal Management System Combining Split Dual Refrigerant Circulation Lines and Indirect Air Heat Exchange

This technology separates the first circulation line for cooling electronic components from the second circulation line for battery pack and cabin thermal management. By performing indirect heat exchange through air circulation between the evaporator and the second heat exchanger, it minimizes pressure loss and reduces system complexity.

Conventional chiller-based systems often suffer from complex configurations because the battery loop and cabin loop share coolant or rely on direct heat exchange. Furthermore, direct heat exchange with the electronic component loop creates unnecessary pressure loss within the refrigerant loop.

This technology features a separate first circulation line for electronic components and a second circulation line for the battery pack and cabin. It uses multiple valve devices to control refrigerant flow and connects the evaporator and second heat exchanger via indirect air circulation, allowing for waste heat recovery and flexible switching between cooling and heating modes. Applicable to integrated thermal management modules for EVs and hybrids, as well as HVAC systems for electric buses and commercial vehicles, it helps reduce winter driving range loss and simplifies refrigerant piping design.

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Key Features:

• A first circulation line through which a first refrigerant flows to cool electronic components via a first compressor and a first heat exchanger
• A second circulation line through which a second refrigerant flows to cool or heat the battery pack via a second compressor and a condenser
• A first branch line that connects the space between the first compressor and the first heat exchanger, and the space between the electronic components and the first heat exchanger, to bypass the first refrigerant
• An accumulator formed in the second circulation line to pass the second refrigerant before it enters the second compressor

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This invention was developed with support from the Ministry of Science and ICT for research into carbon-neutral dry reforming reaction mechanisms based on high-yield, high-selectivity, and high-stability heterogeneous alloy catalysts.

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Long-Life Lithium Metal Batteries Using Bipyridine/Bipyridinium COF as Cathode Additives and Anode Coatings

This technology prevents performance degradation in lithium metal batteries by incorporating 2,2'-bipyridine-based covalent organic frameworks (COFs) into the cathode active material layer and 2,2'-bipyridinium-based COFs into the anode coating layer to suppress metal ion dissolution and induce anion trapping.

High-nickel cathode active materials have historically suffered from structural instability due to nickel ion dissolution. On the anode surface, side reactions with the electrolyte and uneven lithium deposition lead to dendrite formation, which limits battery lifespan.

This technology utilizes 2,2'-bipyridine-based COFs in the cathode to capture metal ions, create ion channels, and suppress nickel dissolution. Simultaneously, it forms a 2,2'-bipyridinium-based COF coating layer (AR-SEI) on the anode to trap anions and promote uniform lithium-ion flux. The manufacturing process is streamlined because the anode COF is derived from the quaternization of the cathode COF. Applicable to next-generation high-energy batteries using high-nickel cathodes and lithium metal anodes, this solution effectively addresses both cathode degradation and anode dendrites using a single material family.

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Key Features:

• A cathode active material layer formed on a current collector, containing a cathode active material and up to 5 wt% of a covalent organic framework.
• A hexagonal framework where the repeating unit of Chemical Formula 1 forms one side, featuring internal pores with diameters of 1.0 to 8.0 nm.
• A coating layer formed on a lithium metal anode substrate with a thickness of 1000 nm or less, containing 10 to 50 wt% of a covalent organic framework.
• A covalent organic framework where 2D sheets are vertically stacked at intervals of 10 nm or less to form a 3D mesoporous structure.

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This invention was developed with support from the Ministry of Science and ICT for a single-ion conductor-based multidimensional free-form power system.

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Non-flammable quasi-solid electrolyte with suppressed anion mobility using a boron-centered polyester crosslinker

This technology features a polyester-based crosslinker with a central boron (B) atom and terminal (meth)acryloyl groups. The boron atom coordinates with anions to suppress their mobility, while the polyester structure creates transport channels for alkali metal cations, simultaneously enhancing ionic conductivity and mobility.

Glycol-based crosslinkers used in conventional gel polymer electrolytes suffer from low electrochemical stability and flammability. Liquid electrolytes face leakage issues, while ionic liquids are limited by low ionic conductivity and high viscosity.

This technology involves mixing a crosslinker—synthesized by reacting a polyol compound with a (meth)acryloyl compound and modifying it with a boron compound—with a porous support and liquid electrolyte to form a quasi-solid state. This ensures non-flammability while leveraging the synergy between the boron and polyester structure to boost cation mobility and electrochemical stability. Applicable to quasi-solid electrolytes for lithium and sodium secondary batteries and leak-proof cells for wearable devices, it reduces fire risks while maintaining ion transport properties comparable to liquid electrolytes.

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Key Features:

• Crosslinker for quasi-solid electrolytes where R1 to R6 are C1 to C8 alkyl groups and terminal Z1 to Z6 are acryloyl or methacryloyl groups
• Crosslinker for quasi-solid electrolytes that coordinates with anions of alkali metal salts, using lithium or sodium salts as the alkali metal salt
• First step of mixing a dihydroxy polyol compound with an amine compound and mixing a (meth)acryloyl compound with a separate solvent
• Third step of adding a boron compound to the intermediate in an inert gas atmosphere, stirring at a two-stage temperature, and drying in a vacuum oven

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This invention was developed with support from the Ministry of Trade, Industry and Energy for the development of high-spec supercapacitors and high-power modules.

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Long-life sodium-manganese oxide cathode material with a mixed spinel phase via lithium substitution

This technology features a heterostructured cathode active material that builds upon a tunnel structure while incorporating a spinel structure within the crystal lattice by substituting lithium into sodium or manganese sites. This suppresses the Jahn-Teller effect of manganese and stabilizes the electronic structure.

Conventional sodium-manganese oxide (NMO) faces structural collapse due to crystal structure transitions and Jahn-Teller distortion caused by changes in the oxidation state of transition metals during charge and discharge. Additionally, it has been limited by low discharge capacity and poor cycle life due to inactive sodium content.

This technology controls the amount of lithium substitution in sodium-manganese oxide to form a spinel structure within the crystal, which oxidizes Mn3+ to Mn4+ to stabilize the electronic structure. Furthermore, the secondary particle structure, composed of nanorod-shaped primary particles, secures a specific surface area of 1.3㎡/g or more, improving ion diffusion paths. Applicable to low-cost sodium batteries for energy storage systems (ESS) and power grid auxiliary batteries, it enables cathode designs that reduce reliance on rare metals while withstanding over 1,000 long-term cycles.

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Key Features:

• A cathode active material for a tunnel-structured sodium-transition metal oxide in which at least one of the sodium or transition metals is substituted with lithium
• A cathode active material containing a spinel structure, where Mn3+ accounts for less than 50% of the total Mn3+ and Mn4+ concentration
• Secondary particles where primary particles contain both tunnel and spinel structures, with the spinel structure increasing as lithium substitution increases
• Secondary particles composed of nanorod-shaped primary particles with longer C-axis lengths, resulting in a specific surface area of 1.3㎡/g or more

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This invention was developed with support from the Ministry of Science and ICT for the development of core and commercialization technologies for interface-optimized, rod-shaped secondary battery materials.

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