sunhuiliang

The conventional Li-ion batteries (LIBs) with organic liquid electrolyte have reached their bottleneck in energy density. The flammable non-aqueous liquid electrolytes used in LIBs also cause serious safety concerns, especially for the large-scale battery packs in electric vehicles. In this context, development of solid-state batteries (SSBs) by replacing the liquid electrolyte with solid-state electrolytes (SSEs) is a promising solution to overcome the limitations of the conventional LIBs. However, there are three general challenges regarding the interface between SSEs and electrode materials in SSBs, including mismatch, chemical reactions, and space charge effects. These interfacial issues are key drawbacks of the performances of SSBs.

Atomic layer deposition (ALD) and molecular layer deposition (MLD), two advanced gas-phase thin-film deposition techniques, are considered ideal strategies for overcoming the interfacial issues for SSBs. Unique and beneficial characteristics of ALD/MLD include low growth temperatures, atomic-scale and stoichiometric deposition, and excellent uniformity and conformity, which are difficult for other coating techniques. In this Review, we summarize the recent developments of ALD/MLD techniques in the application of Li batteries, with a special focus on the transition from liquid to solid cells. Different sections, including the fabrication of interfacial materials by ALD/MLD, interfacial engineering on SSEs and electrodes, and thin-film/3D SSBs designed by ALD/MLD, are discussed in detail. Moreover, the future directions and perspectives of ALD/MLD in interfacial engineering for SSBs are disclosed.

Solid-state batteries (SSBs) have attracted increasing attention as one of the most promising next-generation batteries. However, various challenges remain for SSBs toward practical applications. Particularly, the interfacial issues between solid-state electrolyte (SSEs) and electrodes are critical factors affecting the performances of SSBs. Atomic and molecular layer deposition (ALD and MLD) are considered as ideal strategies for overcoming the interfacial issues facing SSBs. In the past years, promising progress has been reported using ALD/MLD to overcome the interfacial drawbacks in SSBs. In this Review, we summarize the recent progress of ALD/MLD techniques in the application of Li batteries, with a special focus on current progress in the shift from liquid to solid cells. Different sections, including the fabrication of interfacial materials, interfacial engineering on SSEs and electrodes, and thin-film/3D SSBs, are discussed in detail. Moreover, the future directions and perspectives of ALD/MLD in interface engineering for SSBs are disclosed.

A theranostic platform combining synergistic therapy and real-time imaging attracts enormous attention but still faces great challenges, such as tedious modifications and lack of efficient accumulation in tumor. Here, a novel type of theranostic agent, bismuth sulfide@mesoporous silica (Bi₂S₃@mPS) core-shell nanoparticles (NPs), for targeted image-guided therapy of human epidermal growth factor receptor-2 (HER-2) positive breast cancer is developed. To generate such NPs, polyvinylpyrrolidone decorated rod-like Bi₂S₃ NPs are chemically encapsulated with a mesoporous silica (mPS) layer and loaded with an anticancer drug, doxorubicin. The resultant NPs are then chemically conjugated with trastuzumab (Tam, a monoclonal antibody targeting HER-2 overexpressed breast cancer cells) to form Tam-Bi₂S₃@mPS NPs. By in vitro and in vivo studies, it is demonstrated that the Tam-Bi₂S₃@mPS bear multiple desired features for cancer theranostics, including good biocompatibility and drug loading ability as well as precise and active tumor targeting and accumulation (with a bismuth content in tumor being ≈16 times that of nontargeted group). They can simultaneously serve both as an excellent contrast enhancement probe (due to the presence of strong X-ray-attenuating bismuth element) for computed tomography deep tissue tumor imaging and as a therapeutic agent to destruct tumors and prevent metastasis by synergistic photothermal-chemo therapy.

A novel theranostic core–shell nanoparticle is developed to achieve targeted imaging and therapy of breast cancer. The nanoparticle is made of a rod-like Bi₂S₃ core and a porous silica shell functionalized with a tumor-targeting antibody. It can simultaneously attenuate X-ray for targeted tumor imaging by computed tomography and specifically destruct tumor by synergistic photothermal-chemo therapy.

A new technique for direct patterning of functional organic polymers using commercial photolithography setups with a minimal loss of the materials' performances is reported. This result is achieved through novel cross-link agents made by boron- and fluorine-containing heterocycles that can react between themselves upon UV- and white-light exposure.

The electro-optics of thin-film stacks within photovoltaic devices plays a critical role for the exciton and charge generation and therefore the photovoltaic performance. The complex refractive indexes of each layer in heterojunction colloidal quantum dot (CQD) solar cells are measured and the optical electric field is simulated using the transfer matrix formalism. The exciton generation rate and the photocurrent density as a function of the quantum dot solid thickness are calculated and the results from the simulations are found to agree well with the experimentally determined results. It can therefore be concluded that a quantum dot solid may be modeled with this approach, which is of general interest for this type of materials. Optimization of the CQD solar cell is performed by using the optical simulations and a maximum solar energy conversion efficiency of 6.5% is reached for a CQD solid thickness of 300 nm.

The experimental characterization and modeling of the internal optoelectric behavior and exciton generation rate in the quantum dot solids of the heterojunction PbS colloidal quantum dot solar cell is demonstrated. The proposed model shows good agreement with the experimental results, and the fabricated quantum dot solar cell shows a power conversion efficiency of 6.5%.