Lithium has an oxidation state of +1, while oxygen has an oxidation state of -2. This means that in order to form a stable compound, one lithium atom would have to transfer its electron to two oxygen atoms. This would result in the formation of two negatively charged oxygen ions and one positively charged lithium ion. However, because lithium has a larger ionic radius than oxygen, the electrostatic attraction between the ions would be very weak. This would result in the compound being very unstable and likely to decompose.
