Global warming is one of the major challenges of the 21st century. In order to curb it, a change in our energy mix is necessary. However, most renewable energy sources are intermittent and efficient storage devices must be developed. Li-ion technology is among the most interesting solutions. However, the demand for ever greater energy density requires improvement of these systems. One of the most limiting elements is the positive electrode, which has led to a frantic research in this field over the last 40 years. However, most of the lithium intercalation materials listed in the databases have been explored and ideas are running out. The aim of this thesis is then to explore different ways to synthesize new lithium insertion compounds.Thus, in a first step we are interested in low temperature synthesis routes to obtain original materials. Indeed, most of the traditional syntheses are done at high temperature and lead only to the most stable compounds leaving metastable ones inaccessible. Thus, we have studied a hydrothermal synthesis process of ruthenium oxides which allowed us to obtain several new compounds, some of which present interesting electrochemical and/or magnetic properties. Then we have re-explored the chemistry of lithium sulfides left fallow for many years. We have shown that there are still unexplored compositions in this family that can help to understand complex electrochemical mechanisms observed in oxides. Finally, we have studied in turn the electrochemical properties of oxysulfides and halide compounds. This confirms that great discoveries are still to be made and reminds us of the potential of this insertion chemistry beyond energy storage.