Abstract: To improve the water splitting performance of photoelectrode, Wang's group borrowed the lithiation mechanism of Li-ion battery to create ordered lattice strain in the electrode. The stressed lattice induced by Li-ion insertion generates a polarized electric field in the bulk, which greatly improves the bulky charge separation and transfer capability and remarkably promotes the photoelectrocatalytic water splitting. This work paves a new avenue for photo-electrochemical water splitting towards efficient solar hydrogen production. The related work was published in Nature Communications on May 1, 2020.