<p>This paper proposes an asymmetric arc-tube type vibro-impact dielectric elastomer oscillator (AAVI DEO) aimed at improving the energy harvesting (EH) performance of vibro-impact DEGs and enabling energy harvesting from vibrations in arbitrary directions. Built upon the existing AVI DEO, the proposed design introduces asymmetric impact angles, offering a potential approach to enhance EH performance and broaden the effective operating frequency range under both unidirectional and arbitrary-direction excitations. The study first presents the physical model of the AAVI DEO system and establishes its dynamic model under vibration excitation in an arbitrary direction (i.e., resultant excitation in three orthogonal directions). The dynamic model is then validated through experiments. Subsequently, numerical simulations are conducted to investigate the effects of the impact angle and tilt angle parameters on the dynamic behavior and EH performance of the system under unidirectional excitation. Finally, the EH performance under resultant three-directional excitation is examined, considering the joint effects of the impact angle and tilt angle parameters. The results show that under unidirectional excitation, the asymmetric impact angle design can effectively broaden the system effective operating frequency range and increases the output power. Under resultant three-directional excitation, an appropriate impact angle can also achieve high output power and a wider effective operating frequency range; however, the optimal impact angle must be determined by jointly considering the tilt angle of the system and the excitation amplitude (phase angles) and frequency. This work provides new insights and a theoretical basis for the secondary design and optimization of the existing (i.e., completed) AVI DEO.</p>