WeLion semi solid state in-situ process

In-Situ Solidified Electrolyte

The in-situ solidified electrolyte is a WeLion developed and patented technique. The original idea developed for the in-situ solidification was to solve the solid to solid contact issues that arise when assembly solid layers. The 2017 patent [1] lays out the technology and innovation across all chemistries.

The simple steps to the approach is to coat the solid electrolyte on the electrode material particles, combine all of the layers, add liquid electrolyte and then to polymerize this as a built up stack into a semi-solid cell.

In-situ thermal polymerization reaction , photo polymerization reaction , electrochemical solidified SEI/CEI reaction

The six key claims made by WeLion for their technology are:

  1. In-situ Solidification
  2. Solid Electrolyte Blending
  3. Solid Electrolyte Coating the Cathode
  4. Ionic Conductive Separator
  5. Ultra-thin Metallic Lithium Foil
  6. Anode Pre-lithiation

This post has been built based on the support of and sponsorship from: Thermo Fisher Scientific, Eatron Technologies and About:Energy

Also, WeLion claim that the process is compatible with existing processes, equipment and next-generation materials. The process shows a few extra steps, but is basically the standard cell manufacturing process.

Completion of in-situ solidification-related equipment and processes, and verification of manufacturing process and in-situ solidification cell parameters.

So far we have seen examples of NMC (150kWh NIO ES6) and LFP [2] cells and every cell format: pouch, prismatic and cylindrical.

WeLion cell dimensions

WeLion SHE350-106Ah

  • Energy Density
    • 347.5 Wh/kg
    • 746.5 Wh/L
  • Power Density
    • 2019.9 W10s/kg
    • 114.4 Wcont/kg
    • 4339.3 W10s/L

The 106Ah pouch cell has been independently tested by About:Energy [4].

It is refreshing to see the company describing the technology openly and honestly [3]:

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.​

References

  1. A kind of all-solid lithium-ion battery, CN109659595A, Google Patents
  2. World’s first large scale semi-solid-state energy storage project connected to the grid, rho motion
  3. Solid State Technology, WeLion
  4. Welion Solid-State Pouch Battery (350 Wh/kg), About:Energy

See also: Solid Polymer Electrolyte, Solid Electrolyte Comparative Matrix, Cathode-Electrolyte Interface & Catholyte Engineering

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