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Inorganic photochromic material is an available medium to obtain optical information storage. The photochromic property of the inorganic material is mainly from the defects of the host. However, the formation of defects in the host is uncontrollable, in particular, the revisable formation and removement of defects are difficult. Thus, there are few inorganic materials with the revisable photochromism upon the entire light stimulation. Therefore, it is an urgent need to find a suitable approach to design inorganic photochromic materials. Here, the photochromic PbWO4:Yb3+, Er3+ceramic was designed with the help of valence state change of W6+→ W5+and Pb2+→ Pb4+. Upon the 532 nm laser stimulation, the photochromism of the PbWO4:Yb3+, Er3+ceramic was obtained based on the Pb2++ hν (532 nm) → Pb4++ 2e–and W6++ e–+ hν (532 nm) → W5+reaction, resulting in the optical information writing. Under the stimulation of an 808 nm laser, the written optical information was erased based on the W5++ hν (808 nm) → W6++ e–and Pb4++ 2e–+ hν (808 nm) → Pb2+reaction. In addition, the photochromism-induced upconversion emission modification was obtained in the PbWO4:Yb3+, Er3+ceramic, realizing the effective and nondestructive reading out of optical information. The cyclic experiment demonstrated a good reproducibility of both photochromism and upconversion emission modification, exhibiting the potential application of the PbWO4:Yb3+, Er3+ceramic as the optical data storage medium.

Over the past decade, lithium–sulfur (Li–S) batteries have been thought of as promising alternatives for the new generation of battery systems. Although the Li–S batteries possess high-theoretical energy density (2600 Wh kg–1) and capacity (1675 mAh g–1), the problems of poor electron and ion conduction, volumetric expansion, and sulfur immobilization greatly impede the wide applicability of Li–S batteries. Herein, a defect-rich multishelled Co3O4microsphere structure doped with Fe was synthesized via a one-step hydrothermal method and subsequent thermal treatment. The unique multishelled structure provides multiple spatial confinements for lithium polysulfides trapping and buffering the volume variation during cycling. Moreover, the rich oxygen defect designed by controlled Fe doping can provide numerous catalytic sites for polysulfide redox reactions. Attributed to the synergistic effect of structural design and oxygen-defect fabrication, the sulfur composite electrode delivers a notable cycle performance, presenting a much lower capacity fading of 0.017% per cycle over 1000 cycles at 1 C and an excellent rate capability of 571.3 mAh g–1at 5 C. This work proposes a potential approach for designing a transition metal oxide-based multishelled hollow structure combined with oxygen defect, which also offers a new perspective on high-performance Li–S batteries.