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Solid State Technology

Semi-solid-state battery cells replace much of the flammable liquid electrolytes with highly stable solid state electrolytes

Diagram of a lithium-ion battery showing layers: current collector, cathode and liquid electrolyte, separator and liquid electrolyte, anode and liquid electrolyte, and current collector.

Conventional Li-Ion battery

Diagram of a WELION semi solid-state battery showing layers: current collector, cathode with solid electrolyte, separator with hybrid solid-liquid electrolyte, anode with solid electrolyte, and current collector.

WELION
Semi solid state battery

Diagram of an all solid-state battery (ASSB) showing layers: current collector, cathode, solid electrolyte, anode, and current collector.

All solid state battery (ASSB)

The Semi-Solid State

Bridging the gap between conventional liquid electrolyte cells and fully solid-state cells
WELION semi-solid-state battery cells represent an intermediate state between conventional lithium-ion batteries with liquid electrolytes and fully solid-state batteries. They take advantage of the properties of both technologies to increase safety and energy density while controlling costs.​

A safer hybrid electrolyte

A hybrid mixture of solids and liquid electrolyte is simply a safer chemistry
WELION semi-solid-state battery cells use a hybrid electrolyte which is comprised of solid matter surrounded by a liquid electrolyte. The resulting hybrid electrolyte results in cells with a much lower risk of leakage, fire, and explosions that can occur in conventional lithium-ion batteries with a fully liquid electrolyte as there is less flammable liquid in the cell. The unique chemistry also minimizes the risk of „thermal runaway“, a problem that can occur with liquid lithium-ion batteries on the market today.​

Energy density

Increasing energy density through innovative processes and materials
Batteries featuring WELION semi-solid-state cells offer higher energy density than conventional lithium-ion cells, thanks to our hybrid electrolyte chemistry, innovative cell structure, advanced materials, and cutting-edge manufacturing processes.

Processes:
- In-situ Solidified Electrolyte: Creates a stable and uniform electrolyte structure, improving battery safety and longevity.
- Pre-lithiation of the Anode: Boosts the initial capacity and efficiency of the cells, ensuring superior performance from the start.
- Special Mixing of the Solid Electrolyte: Optimizes ionic conductivity and mechanical strength, resulting in higher energy density and better durability.
- Solid Electrolyte Coating of the Cathode: Protects the cathode material, reducing degradation and extending the overall lifespan of the battery.

Materials:
- Ultra-thin Metallic Lithium Foil: Increases energy density, allowing for longer-lasting power in a compact form.
- Ionic Conductive Separator: Improves ionic conductivity, enhancing the overall efficiency and safety of the cell.

Despite these innovations, semi-solid-state cells have not yet matched the electrochemical properties of full solid-state cells, which will undoubtedly achieve even higher energy densities in the near future.

Controlling costs

Cost-efficient, scalable bridge technology between liquid and solid-state cells
Batteries constructed with WELION semi-solid-state cells are more cost-efficient and easier to produce at scale than fully solid-state batteries. Manufacturers can utilize existing lithium-ion battery processing equipment and methods in their production. In contrast, solid-state batteries require new and novel production methods. In this way, semi-solid-state batteries serve as a bridging technology.

Areas of application

Flexible technology for a multitude of applications
WELION semi-solid-state technology will play a particularly important role in lightweight and high-performance electric vehicles (EVs) and energy storage systems, as it can significantly increase range and capacity while decreasing charging times - key factors in driving the change towards e-mobility. Due to the flexibility of WELION technology, our semi-solid-state cells also offers benefits in applications such as portable electronic devices.​

Battery Roadmap

2023

First WELION series semi-solid state production vehicle with 360 Wh/kg 111 Ah cells in NIO car. Range >1000 km on a single charge

2024

Strategic WELION decision to enter motorcycle and LEV market. Products:
>= 310 Wh/kg
>= 670 Wh/l
16 Ah-89 Ah cells

2025

Introduction of new WELION cell formats for E-Bikes Higher Density materials above 360 Wh/kg SOP Cylindrical cells (4695)

2026

Start of 2nd generation technology: WELION Semi-Solid-State Battery Ultra-fast charging for high energy density cells 2C-10C

2027

Next step in energy density

2028

Start of 3rd Generation: Fully solid-state WELION battery Next step in energy density