Power Electronics Lead, Battery System

QuantumScape is on a mission to transform energy storage with solid-state lithium-metal battery technology. The company’s next-generation batteries are designed to enable greater energy density, faster charging and enhanced safety to support the transition away from legacy energy sources toward a lower carbon future. About the role:  As Power Electronics Lead, you will own the complete power conversion architecture - from AC mains or 48V DC bus input through regulated output rails, including the bidirectional charge/discharge path for the integrated solid-state battery pack. You are the chief engineer for the power stage and the technical decision-maker whose topology choices cascade to every other discipline on the team. Why this role matters:  Your architecture decisions define the entire product. Whether the battery sits in-line or on a sidecar bus, whether you go GaN at 48V or Si at 12V, whether the hold-up transfer is sub-millisecond or requires a brief interruption - every downstream engineer builds on top of your choices. This is a rare opportunity to design a power platform from a blank sheet with a technology (solid-state batteries) that fundamentally changes what's possible at rack level. What you'll do: Architect the end-to-end power conversion topology (AC-DC front end, intermediate bus, DC-DC output stage, bidirectional battery converter path) Lead topology trade-off analysis: LLC resonant, phase-shifted full bridge, hybrid approaches, in-line vs. parallel sidecar battery integration Design magnetics (planar transformers, coupled inductors) and select power semiconductors (GaN/SiC FETs, diodes) with thermal derating analysis Define and drive efficiency targets (97%+ titanium-class at rack load) and power density goals within a lOU or 20U shelf envelope Collaborate closely with the firmware/embedded engineer on digital control loop implementation (voltage/current mode compensation, loop bandwidth, phase margin) Work with the battery systems engineer to define the charge/discharge power path, voltage window, and current limits for solid-state cells Design protection circuits (OCP, OVP, OTP, short-circuit) and define fault response behavior Bring up and validate prototype power stages on the bench, iterating through bringup, thermal characterization,and efficiency optimization Interface with the PCB layout contractor to ensure EMI-conscious layout, proper creepage/clearance,and power plane integrity Skills you’ll  need: 10+ years designing multi-kW AC-DC or DC-DC power converters that shipped in volume Relevant Bachelor’s degree plus a minimum of 12+ years of experience or a relevant Master’s degree and 10+ years of experience or a relevant Ph.D. and a minimum of 8+ years Deep expertise in at least two converter topologies (LLC, PSFB, DAB, CLLC, or equivalent) Hands-on magnetics design experience (core selection, winding strategy, loss modeling) Experience with digital power control…