High Performance Li‐ion battery Anodes based on Si Nano core in an LATP Matrix with better Electrolyte Compatibility and Temperature Resistance

Abstract

Novel core/matrix morphologies of Silicon nanostructures/ LATP ceramics are synthesized through a sol ‐ gel assisted method. The Li1.3 Al0.3 Ti1.7(PO4)3 powders were coated on Si nanoparticles as an artificial SEI layer selectively conducting Li cations, which also prevents the formation of the thick natural SEI layer formation, improving the cyclic stability. The composite anodes exhibited a specific capacity of discharge capacities of 1789 mA h g−1 at 0.1 C in the ionic liquid electrolyte LiTFSI‐Pyr14TFSI. They cycle 500 times with a capacity retention of more than 75%. It is assumed that the promising electrochemical characteristics of the composite anode films are due to the absence of direct contact between the Si nanoparticles and the electrolyte and the presence of LATP providing an efficient and quick pathway for lithium ion transport and acts as a Li ion reservoir. The electrodes also show promising results with suitable ionic liquid based electrolytes at high temperature. Hence the conclusions from the present study projects LATP−Si composite films as a promising anode material for LIBs, with high capacities and long cycling stabilities at room temperature as well as high temperature.

Designing double-layered Si and Si/LATP nanocomposite anode for high-voltage aqueous lithium-ion batteries

“…The LATP, while acting like a protective layer, could also contribute towards the anode capacity as evidenced by the CV curves. It is well versed in the literature that LATP does take part in the redox reaction (Ti 4+ / Ti 3+ ) while the Li 1.3 Al 0.3 Ti 1.7 (PO 3 ) 4 is converted to Li 3 Al 0.3 Ti 1.7 (PO 3 ) 4 [22]. The significant factor is that the reduced form of LATP maintains the NASICON structure and Li superionic conductivity and has also got a better diffusion and higher ion conductivity of Lithium [23].…”

“…However, it is prevented by the unique design of the anode wherein the Si nanoparticles are protected by the LATP-polymer matrix. Since only Li + ions and not water or protons could enter inside the coating, due to the unique properties of LATP together with the presence of the hydrophobic polymer, hydrogen production is prevented [22][23][24][25]. Moreover, the Li + ions outside the coating are in a very stable position with a higher potential without taking part in the gas evolution process.…”

“…The tiny plateau at around 0.6 V could be correlated with the additional reactions happening below 0.8 V contributed by the LATP component. The [PO 4 ] tetrahedra in LATP act as an electron donor/acceptor during the intercalation and deintercalation of Li ions within the LATP crystal structure [22]. Since this feature is absent in the CV curves, the CV studies were also done at a lower scan rate of 0.1 mV s −1 where the peaks at around 0.58 V appeared (SI-IV (b)).…”

Interface engineering towardhigh‐efficiencyalloy anode for next‐generation energy storage device

“…The formed the AlPO 4 layer coating improves electrolyte wettability on Al anode and eliminates the ENA, leading homogenous lithiation/delithiation during cycling (Figure 7B). Besides, Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 regarded as a commonly used solid electrolyte, can also be adopted as an artificial SEI layer on Si anode to provide an efficient and fast pathway for Li + transport, which inhibit formation of the thick natural SEI 93 . Li 3 P nanolayer can be constructed on the surface of Si as a stable, ionically conductive protective layer to reduce the direct contact between Si and electrolytes and suppresses side reactions 94…”