Sintering in Battery Electrode Production

How to make thin-film solid-state battery electrodes by sintering?

Solid-state battery electrodes can be made by depositing a metal oxide film on a conductive substrate followed by sintering. The manufacturing process includes:

  1. Depositing a film on a conductive substrate by electrophoresis from a particle suspension.
  1. The resultant membrane film is dried and undergoes thermal fusion treatment by sintering. 
  1. The sintering temperature is maintained below 0.3 times the melting temperature to maintain film thickness below 20 microns.

How to manufacture nanostructured carbon electrodes by sintering?

Nanostructured carbon electrodes can be manufactured by pyrolyzing a carbon-based paste followed by sintering. The production steps are:

  1. Preparing a paste by mixing a mass of nanostructured carbon particles with a fluid source of dissolved carbon. 
  1. The paste is pyrolyzed such that the dissolved carbon source forms solid carbon within a cohesive body of the nanostructured carbon particles. 
  1. The cohesive body is sintered at a pressure between 10 MPa to 1,000 MPa to form contacts between adjacent nanostructured carbon particles.  

How to make high-energy density battery electrodes by sintering? 

A high energy density battery electrode can be made by sintering lithium cobaltite (“LCO”; LiCoO2, LixCoO2 with 0<x<1) grains.  

The LCO grains are sintered to form a self-supporting sheet with porous passages. 

The electrode can further include a solid electrolyte of lithium phosphosulfide (“LPS”; e.g., 75Li2S·25P2S5 and Li7P3S11) overlaying the surface of the sheet and extending into the porous passages.  

How can sintered battery electrodes be manufactured with minimal material degradation?

Cold sintering can be used for manufacturing sintered solid-state electrolytes at very low temperatures without any degradation. 

Cold sintering is a process of combining an inorganic compound, in particle form (e.g., ceramic), with a solvent that can partially solubilize the inorganic compound to form a mixture. 

Pressure and a low temperature are applied to the mixture to evaporate the solvent. The inorganic compound densifies to form sintered electrolyte. 

How to make fast-charging battery electrodes by sintering? 

Cathodes for fast-charging batteries can be manufactured from active material particles of niobium and titanium.  The manufacturing process includes:

  1. The active material particles form a composite phase which includes a carbon-containing compound on the surface. 
  1. The composite particles are sintered at a temperature between 650° C to 900° C in an inert gas atmosphere. This makes a carbon-coated cathode with high crystallinity and conductivity. 

Sintering in the above-described temperature range also removes hydrogen present in the phase. 

More articles on sintering