General Motors Developments in Solid-State Battery Technology

Reducing interfacial impedance between solid electrolytes and solid electrodes in solid-state batteries by incorporating thin layers of liquid metal between them. The liquid metal composition, containing gallium, is applied to the solid electrode and electrolyte surfaces in a controlled environment with oxygen to form oxide coatings that reduce surface tension and improve wetting. The liquid metal fills in surface voids and forms continuous interfacial layers between the solids, improving contact and charge transfer.

Source

Semi-solid electrolyte system for solid-state lithium-ion and lithium metal batteries that provides improved stability and ionic conductivity. The system uses a combination of oxysulfide solid electrolyte and a solvated ionic liquid as the electrolyte. The oxysulfide solid electrolyte facilitates ion transfer between the electrodes and also acts as a separator. The solvated ionic liquid fills some of the pores in the separator to further enhance ionic conductivity. This allows high ionic conductivity and current density at lower stack pressures compared to just using the solid electrolyte. It also provides chemical stability and longer cell life compared to just using the solvated ionic liquid.

Source

Battery cell design with functionalized separators to improve performance and safety. The separator between the anode and cathode contains a lithium-ion conductive solid electrolyte and an active capacitor material. This functionalized separator allows high current density, reduces internal resistance, and mitigates thermal runaway compared to regular separators. It also provides capacitive energy storage to smooth out current peaks during charging and discharging.

Source

A solid-state battery design using an elastomer layer between the solid electrolyte and silicon anode to mitigate volume expansion and cracking of the anode during charging. The elastomer layer contains a plasticizer and a lithium ion conductive medium. The elastomer absorbs the anode expansion and contracts during charging/discharging to prevent cracking and pulverization. It also improves ionic interface between the solid electrolyte and anode. The elastomer layer is sandwiched between the solid electrolyte and silicon anode in the battery cell.

Source

Anode electrode for all-solid-state batteries with patterned silicon to improve performance and lifetime. The anode has arrays of silicon pillars arranged in a pattern with empty spaces between. This allows Si expansion during charging without cracking, as the pillars compress and the spaces accommodate volume change. The pillars also provide high lithium ion conductivity to the solid electrolyte. The pattern is created by selectively removing silicon or masking before deposition.

Source

All-solid-state battery (ASSB) cells with patterned silicon anodes that improve cycle life and performance compared to traditional solid-state batteries. The anodes have silicon columns arranged in a predetermined pattern with voids between them. The voids allow the silicon to expand during charging without cracking or pulverization like solid silicon anodes do. This reduces stress and extends cycle life. The voids also help relieve stress caused by lithium ion diffusion. The patterned silicon anodes also promote lithium ion conduction between the silicon and solid electrolyte to improve battery performance. The voids are created by laser patterning or masking before depositing the silicon columns.

Source

Reducing impedance and improving cycle life in solid-state lithium metal batteries by forming an interfacial layer between the lithium metal anode and the solid electrolyte. The interfacial layer is formed by coating the lithium metal with a mixture of lithium nitrate, trimethyl phosphate, and dimethoxyethane. This coating reduces side reactions between the lithium and the electrolyte, improves contact, and lowers interfacial impedance compared to bare lithium. The coated lithium metal is then assembled into a solid-state battery cell with the electrolyte.

Source

Bicontinuous solid-state battery separators that address issues like limited energy density and lithium plating in solid electrolytes. The separators have a porous matrix filled with a solid electrolyte powder. The solid electrolyte is dispersed in the matrix pore structure. This allows efficient ionic conduction through the solid electrolyte filled pores while preventing lithium metal deposition in the porous matrix. The porous separator with dispersed solid electrolyte provides a continuous pathway for ionic transport with reduced resistance compared to solid electrolytes alone. The porous matrix also limits lithium metal plating compared to solid electrolytes.

Source

Solid-state battery design with uniformly distributed solid-state electrolyte for improved performance. The batteries have solid electrodes with apertures through them that are filled with a solid-state electrolyte precursor solution. The stack is then heated to solidify the electrolyte and form a homogeneous distribution throughout the battery. This improves contact between electrode particles and electrolyte compared to non-uniform electrolyte distribution. The apertures allow the electrolyte to fill voids and pores in the electrodes.

Source

A high-speed manufacturing method for all-solid-state batteries with improved flexibility and efficiency compared to conventional stacking methods. The method involves continuously fabricating expandable anode electrodes or zigzag stacking continuous cathode electrodes. The expandable anode has a continuous anode current collector with anode material on both sides. The continuous cathode electrodes have cathode material on both sides. The expandable anodes or zigzag stacked cathodes are arranged in an alternating pattern to form the battery cell. This allows faster, more efficient production compared to individually punched electrodes and reduces positioning errors. The use of expandable anodes and zigzag stacking enables higher flexibility in the battery design. The anode and cathode electrodes can be made using roll-to-roll manufacturing techniques. Sulfide-based electrolytes are also used in the battery

Source

Solid state lithium ion batteries with improved cycle life and rate performance by using a fibrillated polymer network in the electrode instead of a binder. The electrode active material, electrolyte, and conductive particles are mixed with fibrillated polymer particles and a processing additive like activated carbon. The mixture is consolidated into a film without solvents, forming a fibrous network with distributed particles. This provides a structurally reinforced electrode without separate binders that can degrade during cycling. The fibrillated polymer network improves cycle life and rate performance compared to conventional binders.

Source

Solid-state lithium-ion battery electrodes with improved cycling performance and capacity retention compared to conventional solid-state batteries. The electrodes have a porous active layer made of a fibrillated polymer network with dispersed solid particles. The fibrillated polymer is a fibrous network with an average fiber diameter of 20-300 nm. The particles include electroactive material, solid electrolyte, and porous fibrillation particles. The fibrous network provides mechanical stability and a high surface area for the solid particles. The solventless fabrication process uses heat and avoids solvents to form the electrode. The fibrillated polymer electrode shows improved cycling performance compared to conventional solid-state electrodes.

Source

Scalable manufacturing process for solid-state batteries using continuous high-speed zigzag stacking of bendable anode and cathode electrodes. The process allows large-scale production of solid-state batteries with improved safety and performance compared to liquid electrolyte batteries like lithium-ion. The process involves continuously bending and stacking the anode and cathode electrodes in a zigzag pattern to form the battery stack. This allows continuous production of solid-state battery cells without the need for cutting and joining of separate electrodes. The bendable electrodes can contain individual anode or cathode layers. The process can use sulfide-based electrolytes for improved safety compared to traditional organic electrolytes.

Source

Tabless solid-state battery design with integrated cell structure and housing for improved energy density and simplified manufacturing compared to conventional tabbed solid-state batteries. The tabless battery has parallel-connected anode and cathode electrodes arranged as a cell core. Multiple cell cores are stacked between plated sheets in the housing. The plated sheets have channels for receiving and positioning the electrodes. Terminals are integrated into the housing end walls. This eliminates the need for external tab connections. The simplified cell structure reduces parts count and improves consistency compared to separate tabbed cells. The integrated design also simplifies cooling and assembly.

Source

Method for manufacturing sulfide impregnated solid state batteries with improved performance and reduced cost compared to conventional methods. The method involves impregnating a sulfide-based solid electrolyte into a partially sealed battery cell instead of mixing it with the active material slurry. This is done by introducing a sulfide electrolyte precursor solution into the cell, evaporating the solvent, curing the electrolyte in situ, densifying it under pressure, and sealing the cell. The impregnated electrolyte forms a tight interface with the electrodes without moisture exposure, improving battery performance.

Source

Free-standing thin electrolyte layer for solid-state batteries with high conductivity and reduced thickness, as well as improved mechanical properties. The electrolyte layer has a porous scaffold and a solution processable solid electrolyte filling the pores. The scaffold provides mechanical support while allowing the electrolyte to penetrate and form a homogenous layer. The scaffold has high porosity (50-90%) to enable easy impregnation of the electrolyte. The electrolyte can be a sulfide-based solid or a mixture of solid and liquid phases. The scaffold can be made of fibers with diameters of 0.01-10 microns and lengths of 1-20 microns. The layer is formed by contacting the scaffold with a precursor solution containing the electrolyte, allowing it to penetrate,

Source

Thin, porous electrolyte layers for solid-state batteries that improve performance and safety. The electrolyte layers contain a solution-processable solid electrolyte material that partially fills the pores of a porous framework. The layers can be made by depositing the electrolyte precursor solution into the framework pores. This allows thin, flexible, and conformable electrolyte layers with high porosity (50-90%) for solid-state batteries. The solid electrolyte material fills the framework pores to provide a conductive pathway for lithium ion movement. The thin, porous electrolyte layers enable better interfacial contact with the battery electrodes and reduce the risk of internal short circuits compared to solid electrolyte layers.

Source

An all-solid-state battery design with improved power capability and energy density. The battery uses a negative electrode made of columnar silicon with in-situ formed sulfide electrolyte. The columnar silicon structure with voids between the pillars allows the sulfide electrolyte to fill the voids. This provides high electrolyte volume filling, reducing interfacial resistance compared to solid electrolyte only. The columnar silicon anode with sulfide electrolyte is formed by contacting a columnar silicon film with a sulfide precursor electrolyte, then removing the solvent to infiltrate the voids.

Source

Solid-state batteries with reduced porosity electrolytes, and methods to make them. The solid electrolyte is represented by Li3AB6 where A is Yttrium, Indium, Scandium, Erbium, or combinations, and B is Chloride, Bromide, ClxBr(x-1), with 0 < x < 1. The battery structure has a separator between the positive and negative electrodes. The positive electrode contains the electroactive material and solid electrolyte. The negative electrode may also have electroactive material. The solid electrolyte layer can be formed simultaneously with the positive electrode. This reduces porosity compared to separate layers. The reduced porosity improves battery performance by reducing electrolyte degradation and preventing short circuits.

Source

<|assistant|> Solid-state batteries for electric vehicles that use sulfide electrolytes inside columnar silicon anodes. The batteries have an electrode structure with a void space filled by a solid sulfide electrolyte. The electrode comprises a stack of hierarchical silicon columns with openings between them. The electrolyte is formed by infiltrating a precursor solution into the silicon stack and then removing the solvent. This avoids the need for liquid electrolytes and separators in all-solid-state batteries. The columnar silicon anodes enable higher capacity compared to planar silicon anodes. The sulfide electrolyte provides stable cycling and intercalation between the silicon and electrode active materials.

Source