Solid-state battery

A solid-state battery (SSB) is an electrical battery that uses a solid electrolyte to conduct ions between the electrodes, instead of the liquid or gel polymer electrolytes found in conventional batteries. Theoretically, solid-state batteries offer much higher energy density than the typical lithium-ion or lithium polymer batteries. While solid electrolytes were first discovered in the 19th century, several problems prevented widespread application. Developments in the late 20th and early 21st century generated renewed interest in the technology, especially in the context of electric vehicles. As of 2026, the solid-state battery market has yet to reach scalability and commercialization. Solid-state batteries can use metallic lithium for the anode and oxides or sulfides for the cathode, improving energy density. The solid electrolyte acts as an ideal separator that allows only lithium ions to pass through, allowing solid-state batteries to potentially solve many liquid electrolyte Li-ion battery problems including flammability, voltage range, unstable electrode interface formation, cycling performance, and mechanical strength. Materials proposed for use as solid electrolytes include ceramics (e.g., oxides, sulfides, phosphates), and solid polymers. Solid-state batteries are found in pacemakers and in RFID and wearable devices.…

A solid-state battery (SSB) is an electrical battery that uses a solid electrolyte to conduct ions between the electrodes, instead of the liquid or gel polymer electrolytes found in conventional batteries. Theoretically, solid-state batteries offer much higher energy density than the typical lithium-ion or lithium polymer batteries. While solid electrolytes were first discovered in the 19th century, several problems prevented widespread application. Developments in the late 20th and early 21st century generated renewed interest in the technology, especially in the context of electric vehicles. As of 2026, the solid-state battery market has yet to reach scalability and commercialization. Solid-state batteries can use metallic lithium for the anode and oxides or sulfides for the cathode, improving energy density. The solid electrolyte acts as an ideal separator that allows only lithium ions to pass through, allowing solid-state batteries to potentially solve many liquid electrolyte Li-ion battery problems including flammability, voltage range, unstable electrode interface formation, cycling performance, and mechanical strength. Materials proposed for use as solid electrolytes include ceramics (e.g., oxides, sulfides, phosphates), and solid polymers. Solid-state batteries are found in pacemakers and in RFID and wearable devices. These batteries offer enhanced safety and higher energy densities. To achieve to widespread adoption over lithium ion batteries, solid-state batteries need to overcome many challenges, including energy density and power density, durability, material costs, and chemical stability. ===1990s and 2000s=== A new class of solid-state electrolyte developed by Oak Ridge National Laboratory, lithium–phosphorus oxynitride (LiPON), emerged in the 1990s. LiPON was successfully used to make thin-film lithium-ion batteries, although applications were limited due to the cost associated with deposition of the thin-film electrolyte, along with the small capacities that could be accessed using the thin-film format. === 2020s=== Many companies have announced readiness to commercialize solid-state batteries at the GWh scale in the 2020s, but their batteries' feasibility or technology readiness is unknown. These announcements include: ProLogium – GWh production capacity by 2022; QuantumScape – GWh production capacity by 2024; Qing Tao – GWh production capacity by 2020; Ampcera – commercial availability by 2021; Panasonic and Toyota – market maturity by 2025; Solid Power, BMW, and Ford – market maturity by end of 2020s; WeLion – GWh production capacity by 2022; StoreDot; Honda – market maturity by 2030; Ionic Materials and Hyundai – market maturity in the 2030s; Donut Lab - GWh production in January 2026; and others. As of January 2026, many of these companies have not commercialized their products and the solid-state battery market has yet to reach scalability and commercialization. ===Perovskite-type=== Meanwhile, Perovskite materials also have great potential for application in solid-state batteries. In order to improve the low efficiency and high pollution of traditional fossil-based energy sources, more and more researchers have put forward the idea of solid-state batteries, which will have a longer lifespan and higher efficiency. However, solid-state batteries still have a lot of safety concerns and drawbacks, so researchers are using a lot of new materials to solve this problem. One such material is perovskite materials. Perovskite materials have excellent ionic conductivity, excellent charge storage capacity and good electrochemical activity, so this material has a very great potential for application in the field of electrochemical energy storage as well as energy conversion. This material is used in many new energy batteries, such as solid state batteries and solar cells. Its general formula is ABX 3 . In ABX 3 , the B ion is surrounded by the X ion octahedron and the A ion is located in the center of the cube. Transition metal perovskite fluoride as a perovskite-type electrode material, has high voltage window, specific capacity and stability, moreover, the structure of transition metal perovskite fluoride facilitates ion migration and its general pseudocapacitance-controlled kinetic features make it have a fast charge transport rate so this material has good electrochemical properties. Thus, more and more researchers focus on this material. Shan et al.'s research not only shows that lithium ions can be inserted into the lattice of perovskite oxides, but also demonstrates that perovskite oxides, with its high ionic conductivity, can be used as an electrode material. For the transition metal perovskite fluoride, it has a fast charge transport rate, high energy density and high stability because it has metal-fluorine bond and the strong electronegativity of fluorine. Jiao et al. used solvothermal method to make the perovskite-type fluoride with a hollow micrometer spherical structure, after testing, this material shows a good retention rate like it has capacity of 142 mAh/g after 1000 cycles at 0.1 A/g. === Interfacial instability=== The interfacial instability of the electrode-electrolyte has always been a serious problem in solid-state batteries. After solid-state electrolyte contacts with the electrode, the chemical and/or electrochemical side reactions at the interface usually produce a passivated interface, which impedes the diffusion of Li + across the electrode-SSE interface. Upon high-voltage cycling, some SSEs may undergo oxidative degradation. \sigma_{creep} = \left(\frac{\dot{\varepsilon}}{A_c}\right)^{1/m}\exp{\left(\frac{Q_c}{mRT}\right)} Where R is the gas constant, T is temperature, \dot{\varepsilon} is the uniaxial strain rate, \sigma_{creep} is the creep stress, and for lithium metal m = 6.6 , Q_c = 37\,\mathrm{kJ} \cdot \mathrm{mol}^{-1} , A_c^{-1/m}=3\times 10^5\,\mathrm{Pa} \cdot \mathrm{s}^{-1} . For lithium metal to be used as an anode, great care must be taken to minimize the cell pressure to relatively low values on the order of its yield stress of 0.8 MPa. The normal operating cell pressure for lithium metal anode is anywhere from 1-7 MPa. Some possible strategies to minimize stress on the lithium metal are to use cells with springs of a chosen spring constant or controlled pressurization of the entire cell. Another strategy may be to sacrifice some energy capacity and use a lithium metal alloy anode which typically has a higher melting temperature than pure lithium metal, resulting in a lower propensity to creep. While these alloys do expand quite a bit when lithiated, often to a greater degree than lithium metal, they also possess improved mechanical properties allowing them to operate at pressures around 50 MPa. This higher cell pressure also has the added benefit of possibly mitigating void formation in the cathode. === Development of thin-film system=== Lithium–oxygen and nitrogen-based polymer thin-film electrolytes has got fully used in solid-state batteries. Non-Li based thin-film solid-state batteries have been studied, such as Ag-doped germanium chalcogenide thin-film solid-state electrolyte system. Barium-doped thin-film system has also been studied, which thickness can be 2 μm at least. In addition, Ni can also be a component in thin film. There are also other methods to fabricate the electrolytes for thin-film solid-state batteries, which are 1.electrostatic-spray deposition technique, 2. DSM-Soulfill process and 3. Using MoO 3 nanobelts to improve the performance of lithium-based thin-film solid-state batteries. ==External links==

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