High entropy oxides (HEOs) are a new class of materials that show promise for reversible energy storage. These materials are composed of multiple metal cations in a single-phase crystal structure, leading to unique properties due to entropy stabilization. This study investigates the electrochemical properties of HEOs, particularly their lithium storage capacity and cycling stability. The results show that entropy stabilization significantly improves the storage capacity and cycling stability of HEOs. The electrochemical behavior of HEOs depends on the individual metal cations present, allowing for the tailoring of electrochemical properties by adjusting the elemental composition. The demand for energy storage devices, such as batteries, has increased rapidly, and Li-ion batteries are the most commonly used. However, other Li-storage schemes, such as conversion or alloying, are being explored for higher capacity systems. HEOs, which are based on entropy stabilization, have shown promising results in terms of electrochemical performance. The study reports that HEOs can be cycled over 500 times without significant capacity degradation, and their electrochemical performance can be fine-tuned by adjusting the elemental composition. The study also compares HEOs with medium entropy compounds and finds that HEOs exhibit better electrochemical performance. The stability of HEOs is attributed to entropy stabilization, which helps maintain the rock-salt structure during lithiation and delithiation. The study also shows that the removal of a single element from a HEO can lead to significant changes in its electrochemical properties. The results demonstrate that HEOs have a high capacity retention and exhibit a de-/lithiation behavior that is different from classical conversion materials. The proposed mechanism suggests that during lithiation, some of the cations in the HEO react with lithium to form nano-Li₂O and nano-metal nuclei via a conversion reaction. The rock-salt structure is preserved during this process, and the participating ions remain "trapped" inside the host matrix, allowing them to diffuse back into the crystal structure during subsequent oxidation processes. This mechanism contributes to the high stability and cycling performance of HEOs. The study concludes that HEOs are very promising materials for reversible electrochemical energy storage.High entropy oxides (HEOs) are a new class of materials that show promise for reversible energy storage. These materials are composed of multiple metal cations in a single-phase crystal structure, leading to unique properties due to entropy stabilization. This study investigates the electrochemical properties of HEOs, particularly their lithium storage capacity and cycling stability. The results show that entropy stabilization significantly improves the storage capacity and cycling stability of HEOs. The electrochemical behavior of HEOs depends on the individual metal cations present, allowing for the tailoring of electrochemical properties by adjusting the elemental composition. The demand for energy storage devices, such as batteries, has increased rapidly, and Li-ion batteries are the most commonly used. However, other Li-storage schemes, such as conversion or alloying, are being explored for higher capacity systems. HEOs, which are based on entropy stabilization, have shown promising results in terms of electrochemical performance. The study reports that HEOs can be cycled over 500 times without significant capacity degradation, and their electrochemical performance can be fine-tuned by adjusting the elemental composition. The study also compares HEOs with medium entropy compounds and finds that HEOs exhibit better electrochemical performance. The stability of HEOs is attributed to entropy stabilization, which helps maintain the rock-salt structure during lithiation and delithiation. The study also shows that the removal of a single element from a HEO can lead to significant changes in its electrochemical properties. The results demonstrate that HEOs have a high capacity retention and exhibit a de-/lithiation behavior that is different from classical conversion materials. The proposed mechanism suggests that during lithiation, some of the cations in the HEO react with lithium to form nano-Li₂O and nano-metal nuclei via a conversion reaction. The rock-salt structure is preserved during this process, and the participating ions remain "trapped" inside the host matrix, allowing them to diffuse back into the crystal structure during subsequent oxidation processes. This mechanism contributes to the high stability and cycling performance of HEOs. The study concludes that HEOs are very promising materials for reversible electrochemical energy storage.