Significance Due to the increasing energy crisis and environmental pollution problems, new energy technologies have been a research hotspot among scientists. Although several energy devices, such as supercapacitors, lithium-ion batteries, solar cells, new energy storage, and power generation devices, having been developed, low energy density, complex preparation process, monotonous structure, and poor mechanical properties have severely limited their application in practical scenarios. Traditional processing methods suffer from complex processes, difficulty in processing microdevices, and the inability to precisely regulate material properties, making it difficult to process high-performance energy devices. With high peak energy density, small heat-affected zone, wide material applicability, high spatial resolution, and customizability, laser processing is often used to increase the energy density of energy devices and integrate microdevices. Thus, it has great research value and application potential in the field of precision processing of advanced materials and devices.

Progress The ultra-high peak power density of the laser can produce strong interactions with the material in a localized area of action, which can finely modulate the microstructure of the electrode surface and significantly increase the energy density of the double-layer capacitor ( Fig. 1). For pseudocapacitor supercapacitors, laser treatment can significantly improve the energy storage capacity by doping active materials or heteroatoms into the electrode material or enhance the kinetics of redox reactions and improve cycling stability through the surface morphology modulation ( Fig. 2).

Lithium-ion batteries play a significant role in life and production. However, the slow reaction kinetic process limits the output power of lithium-ion batteries. The expansion of electrodes during charging and discharging affects the life and safety of lithium batteries. The pulsed laser deposition technology can finely regulate the microstructure of electrodes and develop composite materials, which is conducive to improving the working area of electrodes, reducing the ion transport distance, and increasing the electrical conductivity of electrons and ions; thereby, significantly increasing the energy density and output power of lithium-ion batteries (Fig. 3). Additionally, pulsed laser deposition technology can prepare ultra-thin, dense, and uniform films, which can significantly reduce interface resistance to ensure high ion conductivity and high output power (Fig. 4). Besides, the use of laser etching technology can conveniently control the microstructure of electrode materials or selectively construct composite materials. It can also alleviate the problems of poor cycle stability and low capacity retention caused by volume changes during charging and discharging (Fig. 5).

Laser processing also has important applications in constructing light-absorbing and interfacial layer materials for solar cells. Nanoscale-oriented structures can be prepared on the electrode surface using pulsed laser deposition techniques, which can prevent electron-hole complexation, reduce interfacial resistance, and improve the energy conversion efficiency (Fig. 6). Functional light-absorbing for solar cells can also be prepared using pulsed laser deposition technology. Compared with traditional methods, the grain size of the photoabsorption layer prepared using pulsed laser deposition technology is more uniform and dense. It can easily regulate the structure and band gap of the film, and the microstructure can easily be adjusted to achieve higher light-absorption efficiency (Fig. 7).

Due to the local interaction between the laser and graphene oxide, the direct laser writing technique is often used to prepare water-enabled electric generators. Direct laser writing technology can reduce irradiated graphene oxide regions to conductive reduced graphene oxide to serve as electrodes and interconnecting circuits. Thus, enabling easy in situ construction and integration of water-enabled electric generators on graphene oxide assemblies is realized. However, the thermal effect of laser processing can partially reduce the graphene oxide material. Thus, three-dimensional water-enabled electric generators can be prepared in a controlled manner to obtain higher output power (Fig. 8).

Laser processing has the characteristics of high spatial resolution and strong customization. It can be used to prepare electrode materials with high light transmittance and good flexibility. Simultaneously, the device can be designed into a specific structure to obtain ductility; thus, it has important applications in the field of flexible electronics (Fig. 9).

Conclusions and Prospects Laser processing has obvious advantages and potential in the field of high-performance energy devices. Currently, pulsed laser deposition technology, direct laser writing technology, laser induction technology, and laser etching technology have achieved many successful applications in material modification, device functionalization and miniaturization, electrode preparation, and structural modulation. Supercapacitors, lithium-ion batteries, new energy devices, and flexible electronics prepared using laser processing have significant advantages in terms of energy density, stability, and energy conversion efficiency miniaturization and integration. Although laser processing has made considerable progress in the field of energy devices, there are still many issues to be addressed. For example, the knowledge and understanding of the mechanism of laser-material interaction are still imperfect. It is also difficult to control the spatial thickness or form of structural defects using laser processing. Additionally, the current research on laser processing mainly focused on regulating precursor materials; its application in more complex scenarios needs to be further investigated. With a deeper understanding of laser action mechanisms and further development of laser precision control, it is expected that the applications of laser processing in the field of new energy devices will make breakthroughs.