Fig. 3: In operando and ex situ diffraction studies of KTiPO4F.
From: Titanium-based potassium-ion battery positive electrode with extraordinarily high redox potential
a Diffraction patterns of the in operando SXPD of KTiPO4F in K cell in the 6–17° 2Θ range (λ = 0.7239 Å). b Corresponding charge-discharge profile. Indexed reflections are denoted. The highlighted dark-red XRD patterns show tentative boundaries of the two-phase (2P) or solid solution (SS) deintercalation regimes on charge. The discharge behavior of KTiPO4F can be considered symmetric. The asterisk sign (*) designates steady reflections belonging to cell components. c Selected regions of the ex situ XRD patterns of electrodes recovered at various potentials (charge/discharge at C/20 rate, hold for 20 h at every potential).
