Lithium Germanate (Li2GeO3): A High-Performance Anode Material for Lithium-Ion Batteries

Biomimetic Exogenous "Tissue Batteries" as Artificial Power Sources for Implantable Bioelectronic Devices Manufacturing

Implantable bioelectronic devices (IBDs) have gained attention for their capacity to conformably detect physiological and pathological signals and further provide internal therapy. However, traditional power sources integrated into these IBDs possess intricate limitations such as bulkiness, rigidity, and biotoxicity. Recently, artificial "tissue batteries" (ATBs) have diffusely developed as artificial power sources for IBDs manufacturing, enabling comprehensive biological-activity monitoring, diagnosis, and therapy. ATBs are on-demand and designed to accommodate the soft and confining curved placement space of organisms, minimizing interface discrepancies, and providing ample power for clinical applications. This review presents the near-term advancements in ATBs, with a focus on their miniaturization, flexibility, biodegradability, and power density. Furthermore, it delves into material-screening, structural-design, and energy density across three distinct categories of TBs, distinguished by power supply strategies. These types encompass innovative energy storage devices (chemical batteries and supercapacitors), power conversion devices that harness power from human-body (biofuel cells, thermoelectric nanogenerators, bio-potential devices, piezoelectric harvesters, and triboelectric devices), and energy transfer devices that receive and utilize external energy (radiofrequency-ultrasound energy harvesters, ultrasound-induced energy harvesters, and photovoltaic devices). Ultimately, future challenges and prospects emphasize ATBs with the indispensability of bio-safety, flexibility, and high-volume energy density as crucial components in long-term implantable bioelectronic devices.

Zinc vacancy modulated quaternary metallic oxynitride GeZn1.7ON1.8: as a high-performance anode for lithium-ion storage

Zn-defected GeZn1.7ON1.8 (GeZn1.7−xON1.8) was successfully synthesized by a simple ammoniation and acid etching method. This well-designed Zn cation-deficient GeZn1.7−xON1.8 anode shows enhanced lithium-ion storage performance.

Orbital-hybridization-created optical excitations in Li2GeO3

The three-dimensional ternary Li2GeO3 compound presents various unusual essential properties. The main features are thoroughly explored from the first-principles calculations. The concise pictures, the critical orbital hybridizations in Li-O and Ge-O bonds, are clearly examined through the optimal geometric structure, the atom-dominated electronic energy spectrum, the spatial charge densities, the atom and orbital-decomposed van Hove singularities, and the strong optical responses. The unusual optical transitions cover the red-shift optical gap, various frequency-dependent absorption structures and the most prominent plasmon mode in terms of the dielectric functions, energy loss functions, reflectance spectra, and absorption coefficients. Optical excitations, depending on the directions of electric polarization, are strongly affected by excitonic effects. The close combinations of electronic and optical properties can identify a significant orbital hybridization for each available excitation channel. The developed theoretical framework will be very useful in fully understanding the diverse phenomena of other emergent materials.

K-ion and Na-ion storage performances of Co3O4-Fe2O3 nanoparticle-decorated super P carbon black prepared by a ball milling process

The hybridisation of Co₃O₄ and Fe₂O₃ nanoparticles dispersed in a super P carbon matrix is proposed as a favourable approach to improve the electrochemical performance (reversible capacity, cycling stability and rate capability) of the metal oxide electrodes in metal-ion batteries. Hybrid Co₃O₄-Fe₂O₃/C is prepared by a simple, cheap and easily scalable molten salt method combined with ball-milling and used in sodium-ion and potassium-ion batteries for the first time. The electrode exhibits excellent cycling stability and superior rate capability in sodium-ion cells with a capacity recovery of 440 mA h g^-1 (93% retention) after 180 long-term cycles at 50-1000 mA g^-1 and back to 50 mA g^-1. In contrast, Co₃O₄-Fe₂O₃, Co₃O₄ and Fe₂O₃ electrodes display unsatisfactory electrochemical performance. The hybrid Co₃O₄-Fe₂O₃/C is also reactive with potassium and capable of delivering a reversible capacity of 220 mA h g^-1 at 50 mA g^-1 which is comparable with the most reported anode materials for potassium-ion batteries. The obtained results broaden the range of transition metal oxide-based hybrids as potential anodes for K-ion and Na-ion batteries, and suggest that further studies of these materials with potassium and sodium are worthwhile.