Aimed at the hard-switching issues associated with the traditional zero current switching (ZCS) switched capacitor converters (SCCs), a zero voltage and zero current switching (ZVZCS) DC-DC SCC based on an LC auxiliary network is proposed, which can achieve zero voltage switching (ZVS) for all switches throughout the entire operating range. Under certain conditions, it can also simultaneously achieve both the ZVS and ZCS, significantly reducing the switching losses. On this basis, an in-depth investigation into the impact of dead time on converters is conducted, revealing a quantitative relationship between dead time selection under different load conditions and converter loss distribution. Subsequently, a design methodology for key parameters of auxiliary networks based on dead time is put forward. Finally, based on the proposed ZVZCS SCC, a 24 V DC-12 V DC experimental prototype with 100 W was constructed with a peak efficiency of 99.07%, thus validating the correctness of the theoretical analysis.