LFP as initiator of in-battery polymerization of conducting polymers for high-rate-charging cathodes

A cathode for fast charging lithium ion cells, the cathode prepared from a cathode formulation comprising:

• cathode material having spinel or layered structure,
• olivine-based cathode material, having an olivine-based structure, and being between 5 wt % and 10 wt % of the cathode material, wherein the olivine-based cathode material comprises AzMXO4, wherein A is Li, alone or partially replaced by at most 10% of Na and/or K;
• 0<z≤1, M is at least 50% of Fe(II) or Mn(II) or mixture thereof;
• and XO4 is PO4, alone or partially replaced by at most 10 mol % of at least one group selected from the group consisting of SO4 and SiO4,
• binder material, and
• monomer and/or oligomer material selected to polymerize into a conductive polymer upon partial delithiation of the olivine-based structure cathode material during at least a first charging cycle of a cell having the cathode, wherein the monomer and/or oligomer material comprises monomers and/or oligomers of at least one of pyrrole, aniline, thiophene, phenyl mercaptan, furan, phenol, ethylenedioxythiophene and styrenesulfonate,
• wherein:
• the monomer and/or oligomer material is in its pristine form in the cathode prior to the first charging cycle of the cell,
• the partial delithiation is carried out electrochemically during the first charging cycle of the cell, and
• during the first charging cycle of the cell, the monomer and/or oligomer material is polymerized;
• and
• wherein the partial delithiation increases a capacity of the cathode during fast charging of the fast charging lithium ion cells at rates of 5 C to 15 C.