Understanding the Improved Kinetics and Cyclability of a Li₂MnSiO₄ Cathode with Calcium Substitution

Abstract

Limited practical capacity and poor cyclability caused by sluggish kinetics and structural instability are essential aspects that constrain the potential application of LiMnSiO cathode materials. Herein, LiMnCa SiO/C nanoplates are synthesized using a diethylene-glycol-assisted solvothermal method, targeting to circumvent its drawbacks. Compared with the pristine material, the Ca-substituted material exhibits enhanced electrochemical kinetics and improved cycle life performance. In combination with experimental studies and first-principles calculations, we reveal that Ca incorporation enhances electronic conductivity and the Li-ion diffusion coefficient of the Ca-substituted material, and it improves the structural stability by reducing the lattice distortion. It also shrinks the crystal size and alleviates structure collapse to enhance cycling performance. It is demonstrated that Ca can alleviate the two detrimental factors and shed lights on the further searching for suitable dopants.

The structural origin of enhanced stability of Na3.32Fe2.11Ca0.23(P2O7)2 cathode for Na-ion batteries

“…The observation of spin-orbital of Ca 2p (at around 347.2 eV and 350.9 eV) directly confirms its successful presence in Na 3.32 Fe 2.34 (P 2 O 7 ) 2 ( Fig. S3d) [34]. Moreover, no obvious differences in binding energy are found in the spectra of Na 1s and P 2p (Fig.…”

Research Progress in Multielectron Reactions in Polyanionic Materials for Sodium‐Ion Batteries

“…By summarizing the reported Na 2 MnSiO 4 with >1‐e reactions, we can tentatively conclude that the nanosized particles and highly efficient carbon conductive network enable multielectron reactions of Na 2 MnSiO 4 due to the enhancement in intrinsic low electronic/ionic conductivities . Doping strategies that are widely used in the Li counterparts might be an effective and necessary way to improve the electronic/ionic conductivities substantially in the future works to obtain a decent cycling rate performance . Besides, the still unclear structural evolutions of Na 2 MnSiO 4 need to be interpreted in future due to its extremely attractive theoretical capacity.…”

Recent advances in the design of cathode materials for Li-ion batteries

“…Cation substitution by Mg, Ca, Cr, Ti, V, Ni, Na, Cu or P improved the intrinsic conductivity and increased the Li ion diffusion coefficient. [147][148][149][150][151] 7 Go green with Li-ion batteries Following the growth of the Li-ion batteries industry, the environmental impact of such a technology is critical and must be carefully considered. Cathode materials are the key components in the battery in terms of cost and active weight.…”