Can a Li-ion battery be discharged in CV mode?
I think you misread or mis-interpretted the datasheet.

If it read...    


  Discharge CC (18k) to 2.0V @ 20degC     


.... then I would recognize this as a standard (one time) capacity  test for 3V Lithium coin cells which start at 3V and never ( ever !) for LiPo as this causes permanent damage.  But may ok for max current for Li-Fe.

Li-Fe example

70Ah (ESR 2mΩ)
Charge 3.6V
Discharge 2.0V
Max Charge &lt;=3CA  Max Discharge &lt;4CA or &lt;12CA pulse
Recommended Charge   18A(CC), 3.6V (CV) , 10%A cutoff

Since the model for a battery is similar to a capacitor

Ic=ΔV/ESR+CΔV/dt
For ΔV=Vinit-Vload = 1.6V and applying a CV load of 2.0V to a cell at 3.6V
ESR = 2mΩ, the 1st part becomes  1.6V/2mΩ ~ 800 Amps
 or Pd=I²ESR= 800²*2mΩ = 1280 Watts  ( Pfft or kaboom)