The expansion of use cases of high-power lithium-ion batteries (LIBs) lead to an enormous growth of battery industry. Fast-charging of these batteries is one major issue cell manufacturers and users are both facing nowadays. Faster C-rates enable shorter charging periods but also can lead to cell ageing and in worst cases to safety critical states of the battery. In this case Li-ions cannot intercalate into the anode active material but are reduced at the surface of the layer. After several cycles of fast-charging evolving Li-dendrites can lead to internal shortcuts, separator melting and complete battery failures. The detection of metallic lithium via in situ 7Li-NMR spectroscopy (see Figure 1) is the central objective of this work. A small test cell was developed to fit in the excitation coil of the spectrometer. Therein graphite and NMC811 electrodes were assembled in full cell configuration with a low N/P-ratio. A cellulose-based separator and a 1 M LiPF6 solution in ethylene carbonate and dimethyl carbonate (EC:DMC = 30:70 v/v) with an additive of 1 wt.-% vinylene carbonate as electrolyte were used. This type of cell is capable of operating at least 30 cycles with a charging rate of 0.5 C under ambient atmosphere. During two formation cycles the cell was monitored operando and subsequently charged at temperatures down to 5 °C and C-rates up to 4 C. The Li-metal signal at 270 ppm was obtained when reaching cell voltages of nearly 4.2 V and consequently during the CV step at 4.2 V. Heating the cell in the charged state only slightly reduces the amount of Li-metal. LiC6/12 resonance was obtained around 50 ppm indicating partially lithiated graphite. It emerges above the SOC of ≈ 33 % which is consistent with the stoichiometric amount of LiC12. After discharging Li-metal is removed, the LiC6/12 resonance disappears and the initial state can be reproduced. By using a calibration cell where the anode is replaced with bare copper the amount of Li-metal can be quantified by linear regression. By resting the cell for four days in the charged state after 4 C pulse-charging at room temperature, Li0 signal disappeared and dead lithium remained. These results show a strong temperature-dependency and kinetic hindrance of lithium diffusion in graphite.