A key challenge hindering the mass adoption of Lithium-ion and other next-gen chemistries in advanced battery applications such as hybrid/electric vehicles (xEVs) has been management of their functional performance for more effective battery utilization and control over their life. Contemporary battery management systems (BMS) reliant on monitoring external parameters such as voltage and current to ensure safe battery operation with the required performance usually result in overdesign and inefficient use of capacity. More informative embedded sensors are desirable for internal cell state monitoring, which could provide accurate state-of-charge (SOC) and state-of-health (SOH) estimates and early failure indicators. Here we present a promising new embedded sensing option developed by our team for cell monitoring, fiber-optic

Durability of high-energy throughput batteries is a prerequisite for electric vehicles to penetrate the market. Despite remarkable progresses in silicon anodes with high energy densities, rapid capacity fading of full cells with silicon–graphite anodes limits their use. In this work, we unveil degradation mechanisms such as Li+ crosstalk between silicon and graphite, consequent Li+ accumulation in silicon, and capacity depression of graphite due to silicon expansion. The active material properties, i.e. silicon particle size and graphite hardness, are then modified based on these results to reduce Li+ accumulation in silicon and the subsequent degradation of the active materials in the anode. Finally, the cycling performance is tailored by designing electrodes to regulate Li+ crosstalk. The resultant full cell with an areal capacity of 6 mAh cm−2 has a cycle life of >750 cycles the volumetric energy density of 800 Wh L−1 in a commercial cell format.

The crystal structures and electrochemical properties of α-, β-, γ-, and δ-MnO 2 , synthesized by a redox method under various conditions, were studied for the application of MnO 2 as a positive electrode in a fuel cell/battery (FCB) system. The effects of potassium ion concentration (0-10 M) and temperature (60-160 • C) on the morphology of synthesized MnO 2 were investigated by X-ray diffraction, scanning electron microscopy, and the Brunauer-Emmett-Teller method. In addition, the charge and discharge characteristics, and life cycle performance of MnO 2 as a positive electrode in an FCB system, were investigated by sweep voltammetry and potentiometry. The results indicate that four different crystal structures were obtained by different synthesis conditions: three tunnel structures (α-, β-, and γ-MnO 2 ) and one layered structure (δ-MnO 2 ). The effects of precipitation conditions were mapped and summarized in a phase diagram. Electrochemical testing showed that MnO 2 with small tunnel structures (i.e., βand γ-MnO 2 ) exhibit better life cycle performance than either large tunnel structure α-MnO 2 or layered δ-MnO 2 . Based on XRD analysis carried out after cycling, a schematic diagram is proposed to explain the degradation of the different MnO 2 compounds.

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